diff --git a/CMakeLists.txt b/CMakeLists.txt
index 59e1356..466e964 100755
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -40,6 +40,7 @@
 cmake_minimum_required (VERSION 2.8.8)
 
 project(EPANET)
+add_subdirectory(run)
 add_subdirectory(tools/epanet-output)
 
 IF (BUILD_TESTS)
@@ -51,6 +52,7 @@ set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
 set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
 
+
 # Sets the position independent code property for all targets
 SET(CMAKE_POSITION_INDEPENDENT_CODE ON)
 
@@ -66,40 +68,25 @@ IF (MSVC)
 ENDIF (MSVC)
 
 
-#include_directories(include src)
-
-
 # configure file groups
-file(GLOB EPANET_SOURCES src/*.c)
-#set(EPANET_API_HEADER include/epanet2.h)
-set(EPANET_CLI_SOURCES run/main.c)
-
-file(GLOB EPANET_LIB_ALL src/*)
+file(GLOB EPANET_SOURCES src/*.c src/util/*.c)
+file(GLOB EPANET_LIB_ALL src/* src/util/*)
 source_group("Library" FILES ${EPANET_LIB_ALL})
-source_group("CLI" REGULAR_EXPRESSION "run/.*")
 
 
 # the shared library
 add_library(epanet SHARED ${EPANET_SOURCES})  #${EPANET_API_HEADER})
 target_include_directories(epanet PUBLIC ${PROJECT_SOURCE_DIR}/include)
 
+
 # create export lib so we can link against dll using Visual Studio
-#include(GenerateExportHeader)
-#GENERATE_EXPORT_HEADER(epanet
-#    BASE_NAME epanet
-#    EXPORT_MACRO_NAME DLLEXPORT
-#    EXPORT_FILE_NAME epanet_export.h
-#    STATIC_DEFINE SHARED_EXPORTS_BUILT_AS_STATIC)
-#
-#file(COPY ${CMAKE_CURRENT_BINARY_DIR}/epanet_export.h
-#    DESTINATION ${CMAKE_CURRENT_SOURCE_DIR}/include)
+add_definitions(-D WITH_GENX)
+include(GenerateExportHeader)
+GENERATE_EXPORT_HEADER(epanet
+    BASE_NAME epanet
+    EXPORT_MACRO_NAME DLLEXPORT
+    EXPORT_FILE_NAME epanet_export.h
+    STATIC_DEFINE SHARED_EXPORTS_BUILT_AS_STATIC)
 
-
-# the standalone executable
-add_executable(runepanet ${EPANET_CLI_SOURCES})
-
-if(NOT MSVC)
-    target_link_libraries(runepanet LINK_PUBLIC epanet m)
-else(NOT MSVC)
-	target_link_libraries(runepanet LINK_PUBLIC epanet)
-endif(NOT MSVC)
+file(COPY ${CMAKE_CURRENT_BINARY_DIR}/epanet_export.h
+    DESTINATION ${CMAKE_CURRENT_SOURCE_DIR}/include)
diff --git a/include/epanet2.h b/include/epanet2.h
index a709d2f..e6d91c6 100644
--- a/include/epanet2.h
+++ b/include/epanet2.h
@@ -30,37 +30,40 @@
   #define EN_API_FLOAT_TYPE float
 #endif
 
-// --- define WINDOWS
-#undef WINDOWS
-#ifdef _WIN32
-  #define WINDOWS
-#endif
-#ifdef __WIN32__
-  #define WINDOWS
-#endif
+#ifdef WITH_GENX
+  #include "epanet_export.h"
+#else 
+  // --- define WINDOWS
+  #undef WINDOWS
+  #ifdef _WIN32
+    #define WINDOWS
+  #endif
+  #ifdef __WIN32__
+    #define WINDOWS
+  #endif
 
-// --- define DLLEXPORT
-#ifndef DLLEXPORT
-  #ifdef WINDOWS
-    #ifdef __cplusplus
-      #define DLLEXPORT extern "C" __declspec(dllexport)
-    #else
-      #define DLLEXPORT __declspec(dllexport) __stdcall
-    #endif // __cplusplus
-  #elif defined(CYGWIN)
-    #define DLLEXPORT __stdcall
-  #elif defined(__APPLE__)
-    #ifdef __cplusplus
-      #define DLLEXPORT
+  // --- define DLLEXPORT
+  #ifndef DLLEXPORT
+    #ifdef WINDOWS
+      #ifdef __cplusplus
+        #define DLLEXPORT __declspec(dllexport)
+      #else
+        #define DLLEXPORT __declspec(dllexport) __stdcall
+      #endif // __cplusplus
+    #elif defined(CYGWIN)
+      #define DLLEXPORT __stdcall
+    #elif defined(__APPLE__)
+      #ifdef __cplusplus
+        #define DLLEXPORT
+      #else
+        #define DLLEXPORT
+      #endif
     #else
       #define DLLEXPORT
     #endif
-  #else
-    #define DLLEXPORT
   #endif
 #endif
 
-//#include "epanet_export.h"
 
 // --- Define the EPANET toolkit constants
 
@@ -276,7 +279,10 @@ extern "C" {
   /**
    @brief The EPANET Project wrapper object
    */
-  typedef struct EN_Project EN_Project;
+  typedef void *EN_ProjectHandle;
+
+  typedef struct EN_Pattern EN_Pattern;
+  typedef struct EN_Curve EN_Curve;
   
   /**
    @brief runs a complete EPANET simulation
@@ -291,7 +297,8 @@ extern "C" {
    as it carries out its computations. If this feature is not
    needed then the argument should be NULL.
    */
-  int  DLLEXPORT ENepanet(char *inpFile, char *rptFile, char *binOutFile, void (*callback) (char *));
+  int  DLLEXPORT ENepanet(const char *inpFile, const char *rptFile, 
+    const char *binOutFile, void (*callback) (char *));
   
   /**
    @brief Initializes an EPANET session
@@ -1161,108 +1168,126 @@ extern "C" {
    Threadsafe versions of all epanet functions
    
    ***************************************************/
-  int  DLLEXPORT EN_createproject(EN_Project **p);
-  int  DLLEXPORT EN_deleteproject(EN_Project *p);
+  int DLLEXPORT EN_createproject(EN_ProjectHandle *ph);
+  int DLLEXPORT EN_deleteproject(EN_ProjectHandle *ph);
 
-  int DLLEXPORT EN_epanet(char *inpFile, char *rptFile, char *binOutFile, void (*callback) (char *));
-  int DLLEXPORT EN_init(EN_Project *p, char *rptFile, char *binOutFile, EN_FlowUnits UnitsType, EN_FormType HeadlossFormula);
-  int DLLEXPORT EN_open(EN_Project *p, char *inpFile, char *rptFile, char *binOutFile);
-  int DLLEXPORT EN_saveinpfile(EN_Project *p, char *filename);
-  int DLLEXPORT EN_close(EN_Project *p);
-  int DLLEXPORT EN_solveH(EN_Project *p);
-  int DLLEXPORT EN_saveH(EN_Project *p);
-  int DLLEXPORT EN_openH(EN_Project *p);
-  int DLLEXPORT EN_initH(EN_Project *p, int EN_SaveOption);
-  int DLLEXPORT EN_runH(EN_Project *p, long *currentTime);
-  int DLLEXPORT EN_nextH(EN_Project *p, long *tStep);
-  int DLLEXPORT EN_closeH(EN_Project *p);
-  int DLLEXPORT EN_savehydfile(EN_Project *p, char *filename);
-  int DLLEXPORT EN_usehydfile(EN_Project *p, char *filename);
-  int DLLEXPORT EN_solveQ(EN_Project *p);
-  int DLLEXPORT EN_openQ(EN_Project *p);
-  int DLLEXPORT EN_initQ(EN_Project *p, int saveFlag);
-  int DLLEXPORT EN_runQ(EN_Project *p, long *currentTime);
-  int DLLEXPORT EN_nextQ(EN_Project *p, long *tStep);
-  int DLLEXPORT EN_stepQ(EN_Project *p, long *timeLeft);
-  int DLLEXPORT EN_closeQ(EN_Project *p);
-  int DLLEXPORT EN_writeline(EN_Project *p, char *line);
-  int DLLEXPORT EN_report(EN_Project *p);
-  int DLLEXPORT EN_resetreport(EN_Project *p);
-  int DLLEXPORT EN_setreport(EN_Project *p, char *reportFormat);
-  int DLLEXPORT EN_getcontrol(EN_Project *p, int controlIndex, int *controlType, int *linkIndex, EN_API_FLOAT_TYPE *setting, int *nodeIndex, EN_API_FLOAT_TYPE *level);
-  int DLLEXPORT EN_getcount(EN_Project *p, EN_CountType code, int *count);
-  int DLLEXPORT EN_getoption(EN_Project *p, EN_Option opt, EN_API_FLOAT_TYPE *value);
-  int DLLEXPORT EN_gettimeparam(EN_Project *p, int code, long *value);
-  int DLLEXPORT EN_getflowunits(EN_Project *p, int *code);
-  int DLLEXPORT EN_setflowunits(EN_Project *p, int code);
-  int DLLEXPORT EN_getdemandmodel(EN_Project *p, int *type, EN_API_FLOAT_TYPE *pmin, EN_API_FLOAT_TYPE *preq,
-                                  EN_API_FLOAT_TYPE *pexp);
-  int DLLEXPORT EN_setdemandmodel(EN_Project *p, int type, EN_API_FLOAT_TYPE pmin, EN_API_FLOAT_TYPE preq,
-                                  EN_API_FLOAT_TYPE pexp);
-  int DLLEXPORT EN_getpatternindex(EN_Project *p, char *id, int *index);
-  int DLLEXPORT EN_getpatternid(EN_Project *p, int index, char *id);
-  int DLLEXPORT EN_getpatternlen(EN_Project *p, int index, int *len);
-  int DLLEXPORT EN_getpatternvalue(EN_Project *p, int index, int period, EN_API_FLOAT_TYPE *value);
-  int DLLEXPORT EN_getaveragepatternvalue(EN_Project *p, int index, EN_API_FLOAT_TYPE *value);
-  int DLLEXPORT EN_getqualtype(EN_Project *p, int *qualcode, int *tracenode);
+  void DLLEXPORT EN_clearError(EN_ProjectHandle ph);
+  int DLLEXPORT EN_checkError(EN_ProjectHandle ph, char** msg_buffer);
+
+  //int DLLEXPORT EN_epanet(EN_ProjectHandle ph, const char *f1, const char *f2,
+	//  const char *f3, void(*pviewprog)(char *));
+  int DLLEXPORT EN_init(EN_ProjectHandle *ph, char *rptFile, char *binOutFile,
+          EN_FlowUnits UnitsType, EN_FormType HeadlossFormula);
+
+  int DLLEXPORT EN_open(EN_ProjectHandle ph, const char *inpFile,
+          const char *rptFile, const char *binOutFile);
+
+  int DLLEXPORT EN_saveinpfile(EN_ProjectHandle ph, char *filename);
+
+  int DLLEXPORT EN_close(EN_ProjectHandle ph);
+  int DLLEXPORT EN_solveH(EN_ProjectHandle ph);
+
+  int DLLEXPORT EN_saveH(EN_ProjectHandle ph);
+  int DLLEXPORT EN_openH(EN_ProjectHandle ph);
+  int DLLEXPORT EN_initH(EN_ProjectHandle ph, int EN_SaveOption);
+  int DLLEXPORT EN_runH(EN_ProjectHandle ph, long *currentTime);
+  int DLLEXPORT EN_nextH(EN_ProjectHandle ph, long *tStep);
+  int DLLEXPORT EN_closeH(EN_ProjectHandle ph);
+  int DLLEXPORT EN_savehydfile(EN_ProjectHandle ph, char *filename);
+  int DLLEXPORT EN_usehydfile(EN_ProjectHandle ph, char *filename);
+
+  int DLLEXPORT EN_solveQ(EN_ProjectHandle ph);
+  int DLLEXPORT EN_openQ(EN_ProjectHandle ph);
+  int DLLEXPORT EN_initQ(EN_ProjectHandle ph, int saveFlag);
+  int DLLEXPORT EN_runQ(EN_ProjectHandle ph, long *currentTime);
+  int DLLEXPORT EN_nextQ(EN_ProjectHandle ph, long *tStep);
+  int DLLEXPORT EN_stepQ(EN_ProjectHandle ph, long *timeLeft);
+  int DLLEXPORT EN_closeQ(EN_ProjectHandle ph);
+  int DLLEXPORT EN_writeline(EN_ProjectHandle ph, char *line);
+
+  int DLLEXPORT EN_report(EN_ProjectHandle ph);
+  int DLLEXPORT EN_resetreport(EN_ProjectHandle ph);
+  int DLLEXPORT EN_setreport(EN_ProjectHandle ph, char *reportFormat);
+
+  int DLLEXPORT EN_getcontrol(EN_ProjectHandle ph, int controlIndex, int *controlType, int *linkIndex, EN_API_FLOAT_TYPE *setting, int *nodeIndex, EN_API_FLOAT_TYPE *level);
+  int DLLEXPORT EN_getcount(EN_ProjectHandle ph, EN_CountType code, int *count);
+  int DLLEXPORT EN_getoption(EN_ProjectHandle ph, EN_Option opt, EN_API_FLOAT_TYPE *value);
+  int DLLEXPORT EN_gettimeparam(EN_ProjectHandle ph, int code, long *value);
+  int DLLEXPORT EN_getflowunits(EN_ProjectHandle ph, int *code);
+  int DLLEXPORT EN_setflowunits(EN_ProjectHandle ph, int code);
+  int DLLEXPORT EN_getpatternindex(EN_ProjectHandle ph, char *id, int *index);
+  int DLLEXPORT EN_getpatternid(EN_ProjectHandle ph, int index, char *id);
+  int DLLEXPORT EN_getpatternlen(EN_ProjectHandle ph, int index, int *len);
+  int DLLEXPORT EN_getpatternvalue(EN_ProjectHandle ph, int index, int period, EN_API_FLOAT_TYPE *value);
+  int DLLEXPORT EN_getaveragepatternvalue(EN_ProjectHandle ph, int index, EN_API_FLOAT_TYPE *value);
+  int DLLEXPORT EN_getqualtype(EN_ProjectHandle ph, int *qualcode, int *tracenode);
   int DLLEXPORT EN_geterror(int errcode, char *errmsg, int maxLen);
-  int DLLEXPORT EN_getstatistic(EN_Project *p, int code, EN_API_FLOAT_TYPE* value);
-  int DLLEXPORT EN_getnodeindex(EN_Project *p, char *id, int *index);
-  int DLLEXPORT EN_getnodeid(EN_Project *p, int index, char *id);
-  int DLLEXPORT EN_getnodetype(EN_Project *p, int index, int *code);
-  int DLLEXPORT EN_getnodevalue(EN_Project *p, int index, int code, EN_API_FLOAT_TYPE *value);
-  int DLLEXPORT EN_getcoord(EN_Project *p, int index, EN_API_FLOAT_TYPE *x, EN_API_FLOAT_TYPE *y);
-  int DLLEXPORT EN_setcoord(EN_Project *p, int index, EN_API_FLOAT_TYPE x, EN_API_FLOAT_TYPE y);
-  int DLLEXPORT EN_getnumdemands(EN_Project *p, int nodeIndex, int *numDemands);
-  int DLLEXPORT EN_getbasedemand(EN_Project *p, int nodeIndex, int demandIndex, EN_API_FLOAT_TYPE *baseDemand);
-  int DLLEXPORT EN_getdemandpattern(EN_Project *p, int nodeIndex, int demandIndex, int *pattIndex);
-  int DLLEXPORT EN_getlinkindex(EN_Project *p, char *id, int *index);
-  int DLLEXPORT EN_getlinkid(EN_Project *p, int index, char *id);
-  int DLLEXPORT EN_getlinktype(EN_Project *p, int index, EN_LinkType *code);
-  int DLLEXPORT EN_setlinktype(EN_Project *p, char *id, EN_LinkType type);
-  int DLLEXPORT EN_getlinknodes(EN_Project *p, int index, int *node1, int *node2);
-  int DLLEXPORT EN_getlinkvalue(EN_Project *p, int index, EN_LinkProperty code, EN_API_FLOAT_TYPE *value);
-  int DLLEXPORT EN_getcurve(EN_Project *p, int curveIndex, char* id, int *nValues, EN_API_FLOAT_TYPE **xValues, EN_API_FLOAT_TYPE **yValues);
-  int DLLEXPORT EN_getheadcurveindex(EN_Project *p, int pumpIndex, int *curveIndex);
-  int DLLEXPORT EN_setheadcurveindex(EN_Project *p, int pumpIndex, int curveIndex);
-  int DLLEXPORT EN_getpumptype(EN_Project *p, int linkIndex, int *outType);
-  int DLLEXPORT EN_getcurvetype(EN_Project *p, int curveIndex, int *outType);
+
+  int DLLEXPORT EN_getstatistic(EN_ProjectHandle ph, int code, EN_API_FLOAT_TYPE* value);
+  int DLLEXPORT EN_getnodeindex(EN_ProjectHandle ph, char *id, int *index);
+  int DLLEXPORT EN_getnodeid(EN_ProjectHandle ph, int index, char *id);
+  int DLLEXPORT EN_getnodetype(EN_ProjectHandle ph, int index, int *code);
+  int DLLEXPORT EN_getnodevalue(EN_ProjectHandle ph, int index, int code, EN_API_FLOAT_TYPE *value);
+  int DLLEXPORT EN_getcoord(EN_ProjectHandle ph, int index, EN_API_FLOAT_TYPE *x, EN_API_FLOAT_TYPE *y);
+  int DLLEXPORT EN_setcoord(EN_ProjectHandle ph, int index, EN_API_FLOAT_TYPE x, EN_API_FLOAT_TYPE y);
+  int DLLEXPORT EN_getnumdemands(EN_ProjectHandle ph, int nodeIndex, int *numDemands);
+  int DLLEXPORT EN_getbasedemand(EN_ProjectHandle ph, int nodeIndex, int demandIndex, EN_API_FLOAT_TYPE *baseDemand);
+  int DLLEXPORT EN_getdemandpattern(EN_ProjectHandle ph, int nodeIndex, int demandIndex, int *pattIndex);
+  int DLLEXPORT EN_getlinkindex(EN_ProjectHandle ph, char *id, int *index);
+  int DLLEXPORT EN_getlinkid(EN_ProjectHandle ph, int index, char *id);
+  int DLLEXPORT EN_getlinktype(EN_ProjectHandle ph, int index, EN_LinkType *code);
+  int DLLEXPORT EN_setlinktype(EN_ProjectHandle ph, char *id, EN_LinkType type);
+  int DLLEXPORT EN_getlinknodes(EN_ProjectHandle ph, int index, int *node1, int *node2);
+  int DLLEXPORT EN_getlinkvalue(EN_ProjectHandle ph, int index, EN_LinkProperty code, EN_API_FLOAT_TYPE *value);
+  int DLLEXPORT EN_getcurve(EN_ProjectHandle ph, int curveIndex, char* id, int *nValues, EN_API_FLOAT_TYPE **xValues, EN_API_FLOAT_TYPE **yValues);
+  int DLLEXPORT EN_getheadcurveindex(EN_ProjectHandle ph, int pumpIndex, int *curveIndex);
+  int DLLEXPORT EN_setheadcurveindex(EN_ProjectHandle ph, int pumpIndex, int curveIndex);
+  int DLLEXPORT EN_getpumptype(EN_ProjectHandle ph, int linkIndex, int *outType);
+  int DLLEXPORT EN_getcurvetype(EN_ProjectHandle ph, int curveIndex, int *outType);
+
   int DLLEXPORT EN_getversion(int *version);
-  int DLLEXPORT EN_setcontrol(EN_Project *p, int cindex, int ctype, int lindex, EN_API_FLOAT_TYPE setting, int nindex, EN_API_FLOAT_TYPE level);
-  int DLLEXPORT EN_setnodevalue(EN_Project *p, int index, int code, EN_API_FLOAT_TYPE v);
-  int DLLEXPORT EN_setlinkvalue(EN_Project *p, int index, int code, EN_API_FLOAT_TYPE v);
-  int DLLEXPORT EN_addpattern(EN_Project *p, char *id);
-  int DLLEXPORT EN_setpattern(EN_Project *p, int index, EN_API_FLOAT_TYPE *f, int len);
-  int DLLEXPORT EN_setpatternvalue(EN_Project *p, int index, int period, EN_API_FLOAT_TYPE value);
-  int DLLEXPORT EN_settimeparam(EN_Project *p, int code, long value);
-  int DLLEXPORT EN_setoption(EN_Project *p, int code, EN_API_FLOAT_TYPE v);
-  int DLLEXPORT EN_setstatusreport(EN_Project *p, int code);
-  int DLLEXPORT EN_setqualtype(EN_Project *p, int qualcode, char *chemname, char *chemunits, char *tracenode);
-  int DLLEXPORT EN_getqualinfo(EN_Project *p, int *qualcode, char *chemname, char *chemunits, int *tracenode);
-  int DLLEXPORT EN_setbasedemand(EN_Project *p, int nodeIndex, int demandIdx, EN_API_FLOAT_TYPE baseDemand);
-  int DLLEXPORT EN_getcurveindex(EN_Project *p, char *id, int *index);
-  int DLLEXPORT EN_getcurveid(EN_Project *p, int index, char *id);
-  int DLLEXPORT EN_getcurvelen(EN_Project *p, int index, int *len);
-  int DLLEXPORT EN_getcurvevalue(EN_Project *p, int curveIndex, int pointIndex, EN_API_FLOAT_TYPE *x, EN_API_FLOAT_TYPE *y);
-  int DLLEXPORT EN_setcurvevalue(EN_Project *p, int curveIndex, int pointIndex, EN_API_FLOAT_TYPE x, EN_API_FLOAT_TYPE y);
-  int DLLEXPORT EN_setcurve(EN_Project *p, int index, EN_API_FLOAT_TYPE *x, EN_API_FLOAT_TYPE *y, int len);
-  int DLLEXPORT EN_addcurve(EN_Project *p, char *id);
-  int DLLEXPORT EN_getrule(EN_Project *p, int index, int *nPremises, int *nTrueActions, int *nFalseActions, EN_API_FLOAT_TYPE *priority);
-  int DLLEXPORT EN_setrulepriority(EN_Project *p, int index, EN_API_FLOAT_TYPE priority);
-  int DLLEXPORT EN_getpremise(EN_Project *p, int indexRule, int indexPremise, int *logop, int *object, int *indexObj, int *variable, int *relop, int *status, EN_API_FLOAT_TYPE *value);
-  int DLLEXPORT EN_setpremise(EN_Project *p, int indexRule, int indexPremise, int logop, int object, int indexObj, int variable, int relop, int status, EN_API_FLOAT_TYPE value);
-  int DLLEXPORT EN_setpremiseindex(EN_Project *p, int indexRule, int indexPremise, int indexObj);
-  int DLLEXPORT EN_setpremisestatus(EN_Project *p, int indexRule, int indexPremise, int status);
-  int DLLEXPORT EN_setpremisevalue(EN_Project *p, int indexRule, int indexPremise, EN_API_FLOAT_TYPE value);
-  int DLLEXPORT EN_gettrueaction(EN_Project *p, int indexRule, int indexAction, int *indexLink, int *status, EN_API_FLOAT_TYPE *setting);
-  int DLLEXPORT EN_settrueaction(EN_Project *p, int indexRule, int indexAction, int indexLink, int status, EN_API_FLOAT_TYPE setting);
-  int DLLEXPORT EN_getfalseaction(EN_Project *p, int indexRule, int indexAction, int *indexLink, int *status, EN_API_FLOAT_TYPE *setting);
-  int DLLEXPORT EN_setfalseaction(EN_Project *p, int indexRule, int indexAction, int indexLink, int status, EN_API_FLOAT_TYPE setting);
-  int DLLEXPORT EN_getruleID(EN_Project *p, int indexRule, char* id);
-  int DLLEXPORT EN_addnode(EN_Project *p, char *id, EN_NodeType nodeType);
-  int DLLEXPORT EN_addlink(EN_Project *p, char *id, EN_LinkType linkType, char *fromNode, char *toNode);
-  int DLLEXPORT EN_deletenode(EN_Project *p, int nodeIndex);
-  int DLLEXPORT EN_deletelink(EN_Project *p, int linkIndex);
+
+  int DLLEXPORT EN_setcontrol(EN_ProjectHandle ph, int cindex, int ctype, int lindex, EN_API_FLOAT_TYPE setting, int nindex, EN_API_FLOAT_TYPE level);
+  int DLLEXPORT EN_setnodevalue(EN_ProjectHandle ph, int index, int code, EN_API_FLOAT_TYPE v);
+  int DLLEXPORT EN_setlinkvalue(EN_ProjectHandle ph, int index, int code, EN_API_FLOAT_TYPE v);
+  int DLLEXPORT EN_addpattern(EN_ProjectHandle ph, char *id);
+  int DLLEXPORT EN_setpattern(EN_ProjectHandle ph, int index, EN_API_FLOAT_TYPE *f, int len);
+  int DLLEXPORT EN_setpatternvalue(EN_ProjectHandle ph, int index, int period, EN_API_FLOAT_TYPE value);
+  int DLLEXPORT EN_settimeparam(EN_ProjectHandle ph, int code, long value);
+  int DLLEXPORT EN_setoption(EN_ProjectHandle ph, int code, EN_API_FLOAT_TYPE v);
+  int DLLEXPORT EN_setstatusreport(EN_ProjectHandle ph, int code);
+  int DLLEXPORT EN_setqualtype(EN_ProjectHandle ph, int qualcode, char *chemname, char *chemunits, char *tracenode);
+
+  int DLLEXPORT EN_getdemandmodel(EN_ProjectHandle ph, int *type, EN_API_FLOAT_TYPE *pmin,
+              EN_API_FLOAT_TYPE *preq, EN_API_FLOAT_TYPE *pexp);
+   int DLLEXPORT EN_setdemandmodel(EN_ProjectHandle ph, int type, EN_API_FLOAT_TYPE pmin,
+              EN_API_FLOAT_TYPE preq, EN_API_FLOAT_TYPE pexp);
+
+  int DLLEXPORT EN_getqualinfo(EN_ProjectHandle ph, int *qualcode, char *chemname, char *chemunits, int *tracenode);
+  int DLLEXPORT EN_setbasedemand(EN_ProjectHandle ph, int nodeIndex, int demandIdx, EN_API_FLOAT_TYPE baseDemand);
+  int DLLEXPORT EN_getcurveindex(EN_ProjectHandle ph, char *id, int *index);
+  int DLLEXPORT EN_getcurveid(EN_ProjectHandle ph, int index, char *id);
+  int DLLEXPORT EN_getcurvelen(EN_ProjectHandle ph, int index, int *len);
+  int DLLEXPORT EN_getcurvevalue(EN_ProjectHandle ph, int curveIndex, int pointIndex, EN_API_FLOAT_TYPE *x, EN_API_FLOAT_TYPE *y);
+  int DLLEXPORT EN_setcurvevalue(EN_ProjectHandle ph, int curveIndex, int pointIndex, EN_API_FLOAT_TYPE x, EN_API_FLOAT_TYPE y);
+  int DLLEXPORT EN_setcurve(EN_ProjectHandle ph, int index, EN_API_FLOAT_TYPE *x, EN_API_FLOAT_TYPE *y, int len);
+  int DLLEXPORT EN_addcurve(EN_ProjectHandle ph, char *id);
+  int DLLEXPORT EN_getrule(EN_ProjectHandle ph, int index, int *nPremises, int *nTrueActions, int *nFalseActions, EN_API_FLOAT_TYPE *priority);
+  int DLLEXPORT EN_setrulepriority(EN_ProjectHandle ph, int index, EN_API_FLOAT_TYPE priority);
+  int DLLEXPORT EN_getpremise(EN_ProjectHandle ph, int indexRule, int indexPremise, int *logop, int *object, int *indexObj, int *variable, int *relop, int *status, EN_API_FLOAT_TYPE *value);
+  int DLLEXPORT EN_setpremise(EN_ProjectHandle ph, int indexRule, int indexPremise, int logop, int object, int indexObj, int variable, int relop, int status, EN_API_FLOAT_TYPE value);
+  int DLLEXPORT EN_setpremiseindex(EN_ProjectHandle ph, int indexRule, int indexPremise, int indexObj);
+  int DLLEXPORT EN_setpremisestatus(EN_ProjectHandle ph, int indexRule, int indexPremise, int status);
+  int DLLEXPORT EN_setpremisevalue(EN_ProjectHandle ph, int indexRule, int indexPremise, EN_API_FLOAT_TYPE value);
+  int DLLEXPORT EN_gettrueaction(EN_ProjectHandle ph, int indexRule, int indexAction, int *indexLink, int *status, EN_API_FLOAT_TYPE *setting);
+  int DLLEXPORT EN_settrueaction(EN_ProjectHandle ph, int indexRule, int indexAction, int indexLink, int status, EN_API_FLOAT_TYPE setting);
+  int DLLEXPORT EN_getfalseaction(EN_ProjectHandle ph, int indexRule, int indexAction, int *indexLink, int *status, EN_API_FLOAT_TYPE *setting);
+  int DLLEXPORT EN_setfalseaction(EN_ProjectHandle ph, int indexRule, int indexAction, int indexLink, int status, EN_API_FLOAT_TYPE setting);
+  int DLLEXPORT EN_getruleID(EN_ProjectHandle ph, int indexRule, char* id);
+  int DLLEXPORT EN_addnode(EN_ProjectHandle ph, char *id, EN_NodeType nodeType);
+  int DLLEXPORT EN_addlink(EN_ProjectHandle ph, char *id, EN_LinkType linkType, char *fromNode, char *toNode);
+  int DLLEXPORT EN_deletenode(EN_ProjectHandle ph, int nodeIndex);
+  int DLLEXPORT EN_deletelink(EN_ProjectHandle ph, int linkIndex);
   
 #if defined(__cplusplus)
 }
diff --git a/run/CMakeLists.txt b/run/CMakeLists.txt
new file mode 100644
index 0000000..53e792b
--- /dev/null
+++ b/run/CMakeLists.txt
@@ -0,0 +1,28 @@
+# EPANET COMMAND LINE EXECUTABLE
+cmake_minimum_required (VERSION 3.0.2)
+
+
+# Sets for output directory for executables and libraries. 
+set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
+set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
+set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
+
+# Sets the position independent code property for all targets. 
+set(CMAKE_POSITION_INDEPENDENT_CODE ON)
+
+
+# Set up file groups for exe target
+set(EPANET_CLI_SOURCES main.c)
+include_directories(include)
+
+source_group("CLI" FILES ${EPANET_CLI_SOURCES})
+
+
+# Creates the EPANET command line executable
+add_definitions(-D WITH_GENX)
+add_executable(runepanet ${EPANET_CLI_SOURCES})
+if(NOT WIN32)
+    target_link_libraries(runepanet LINK_PUBLIC epanet m)
+else(NOT WIN32)
+    target_link_libraries(runepanet LINK_PUBLIC epanet)
+endif(NOT WIN32)
diff --git a/src/epanet.c b/src/epanet.c
index a0ab719..6463c08 100644
--- a/src/epanet.c
+++ b/src/epanet.c
@@ -134,6 +134,10 @@ execute function x and set the error code equal to its return value.
 // in "legacy mode" with the 2.1-style API. 
 EN_Project *_defaultModel;
 
+
+// Local functions
+void errorLookup(int errcode, char *errmsg, int len);
+
 /****************************************************************
 
  LEGACY (v <= 2.1) API: uses global project variable
@@ -157,19 +161,24 @@ EN_Project *_defaultModel;
  **  needed then the argument should be NULL.
  **-------------------------------------------------------------------------
  */
-int DLLEXPORT ENepanet(char *f1, char *f2, char *f3,
-                       void (*pviewprog)(char *)) {
+int DLLEXPORT ENepanet(const char *f1, const char *f2, const char *f3, void (*pviewprog)(char *))
+{
   int errcode = 0;
+
   ERRCODE(EN_createproject(&_defaultModel));
   ERRCODE(EN_open(_defaultModel, f1, f2, f3));
   _defaultModel->viewprog = pviewprog;
+
   if (_defaultModel->out_files.Hydflag != USE) {
     ERRCODE(EN_solveH(_defaultModel));
   }
+
   ERRCODE(EN_solveQ(_defaultModel));
   ERRCODE(EN_report(_defaultModel));
+
   EN_close(_defaultModel);
-  EN_deleteproject(_defaultModel);
+  EN_deleteproject(&_defaultModel);
+
   return (errcode);
 }
 
@@ -184,10 +193,7 @@ int DLLEXPORT ENsaveinpfile(char *filename) {
   return EN_saveinpfile(_defaultModel, filename);
 }
 
-int DLLEXPORT ENclose() {
-    EN_close(_defaultModel);
-    return EN_deleteproject(_defaultModel);
-}
+int DLLEXPORT ENclose() { return EN_close(_defaultModel); }
 
 int DLLEXPORT ENsolveH() { return EN_solveH(_defaultModel); }
 
@@ -550,36 +556,50 @@ int DLLEXPORT ENdeletenode(int index) {
   return EN_deletenode(_defaultModel, index);
 }
 
-
-int DLLEXPORT EN_epanet(char *inpFile, char *rptFile, char *binOutFile, void(*callback) (char *))
-{
-    return ENepanet(inpFile, rptFile, binOutFile, callback);
-}
-
 /*
 ----------------------------------------------------------------
    Functions for opening & closing the EPANET system
 ----------------------------------------------------------------
 */
 
-/// Create an EPANET project
-int DLLEXPORT EN_createproject(EN_Project **p)
+/// allocate a project pointer
+int DLLEXPORT EN_createproject(EN_ProjectHandle *ph)
+// Note: No error handling available until project allocation
 {
-    EN_Project *project = calloc(1, sizeof(EN_Project));
-    if (project == NULL) return 101;
-    *p = project;
+  int errorcode = 0;
+  EN_Project *project = calloc(1, sizeof(EN_Project));
+
+  if (project != NULL){
+      project->error_handle = new_errormanager(&errorLookup);
+      *ph = project;
+  }
+  else
+      errorcode = -1;
+
+  return errorcode;
+}
+
+int DLLEXPORT EN_deleteproject(EN_ProjectHandle *ph)
+// Note: No error handling available after project deallocation
+{
+    int errorcode = 0;
+    EN_Project *p = (EN_Project*)(*ph);
+
+    if (p == NULL)
+        errorcode = -1;
+    else
+    {
+        dst_errormanager(p->error_handle);
+        free(p);
+
+        *ph = NULL;
+    }
+
     return 0;
 }
 
-/// Delete an EPANET project
-int DLLEXPORT EN_deleteproject(EN_Project *p) 
-{
-  if (p) free(p);
-  p = NULL;
-  return 0;
-}
 
-int DLLEXPORT EN_init(EN_Project *pr, char *f2, char *f3,
+int DLLEXPORT EN_init(EN_ProjectHandle *ph, char *f2, char *f3,
                       EN_FlowUnits UnitsType, EN_FormType HeadlossFormula)
 /*----------------------------------------------------------------
  **  Input:
@@ -600,6 +620,8 @@ int DLLEXPORT EN_init(EN_Project *pr, char *f2, char *f3,
   _fpreset();
 #endif
 
+  EN_Project *pr = (EN_Project*)*ph;
+
   /* Set system flags */
   pr->Openflag = TRUE;
   pr->hydraulics.OpenHflag = FALSE;
@@ -634,10 +656,10 @@ int DLLEXPORT EN_init(EN_Project *pr, char *f2, char *f3,
   // initialize default pattern
   getpatterns(pr);
 
-  return (errcode);
+  return set_error(pr->error_handle, errcode);
 }
 
-int DLLEXPORT EN_open(EN_Project *p, char *f1, char *f2, char *f3)
+int DLLEXPORT EN_open(EN_ProjectHandle ph, const char *f1, const char *f2, const char *f3)
 /*----------------------------------------------------------------
  **  Input:   f1 = pointer to name of input file
  **           f2 = pointer to name of report file
@@ -656,6 +678,8 @@ int DLLEXPORT EN_open(EN_Project *p, char *f1, char *f2, char *f3)
   _fpreset();
 #endif
 
+  EN_Project *p = (EN_Project*)ph;
+
   /* Set system flags */
   p->Openflag = FALSE;
   p->hydraulics.OpenHflag = FALSE;
@@ -676,7 +700,7 @@ int DLLEXPORT EN_open(EN_Project *p, char *f1, char *f2, char *f3)
   ERRCODE(openfiles(p, f1, f2, f3));
   if (errcode > 0) {
     errmsg(p, errcode);
-    return (errcode);
+    return set_error(p->error_handle, errcode);
   }
   writelogo(p);
 
@@ -707,10 +731,10 @@ int DLLEXPORT EN_open(EN_Project *p, char *f1, char *f2, char *f3)
     p->Openflag = TRUE;
   } else
     errmsg(p, errcode);
-  return (errcode);
+  return set_error(p->error_handle, errcode);
 }
 
-int DLLEXPORT EN_saveinpfile(EN_Project *p, char *filename)
+int DLLEXPORT EN_saveinpfile(EN_ProjectHandle ph, char *filename)
 /*----------------------------------------------------------------
  **  Input:   filename = name of INP file
  **  Output:  none
@@ -719,12 +743,15 @@ int DLLEXPORT EN_saveinpfile(EN_Project *p, char *filename)
  **----------------------------------------------------------------
  */
 {
+  EN_Project *p = (EN_Project*)ph;
+  
   if (!p->Openflag)
-    return (102);
-  return (saveinpfile(p, filename));
+	  return set_error(p->error_handle, 102);
+  
+  return set_error(p->error_handle, saveinpfile(p, filename));
 }
 
-int DLLEXPORT EN_close(EN_Project *p)
+int DLLEXPORT EN_close(EN_ProjectHandle ph)
 /*----------------------------------------------------------------
  **  Input:   none
  **  Output:  none
@@ -734,6 +761,8 @@ int DLLEXPORT EN_close(EN_Project *p)
  */
 {
   out_file_t *out;
+
+  EN_Project *p = (EN_Project*)ph;
   
   if (p->Openflag) {
     writetime(p, FMT105);
@@ -777,7 +806,8 @@ int DLLEXPORT EN_close(EN_Project *p)
   p->save_options.SaveHflag = FALSE;
   p->quality.OpenQflag = FALSE;
   p->save_options.SaveQflag = FALSE;
-  return (0);
+
+  return set_error(p->error_handle, 0);
 }
 
 /*
@@ -786,7 +816,7 @@ int DLLEXPORT EN_close(EN_Project *p)
  ----------------------------------------------------------------
  */
 
-int DLLEXPORT EN_solveH(EN_Project *p)
+int DLLEXPORT EN_solveH(EN_ProjectHandle ph)
 /*----------------------------------------------------------------
  **  Input:   none
  **  Output:  none
@@ -798,11 +828,13 @@ int DLLEXPORT EN_solveH(EN_Project *p)
   int errcode;
   long t, tstep;
 
+  EN_Project *p = (EN_Project*)ph;
+
   /* Open hydraulics solver */
-  errcode = EN_openH(p);
+  errcode = EN_openH(ph);
   if (!errcode) {
     /* Initialize hydraulics */
-    errcode = EN_initH(p, EN_SAVE);
+    errcode = EN_initH(ph, EN_SAVE);
     writecon(FMT14);
 
     /* Analyze each hydraulic period */
@@ -821,8 +853,8 @@ int DLLEXPORT EN_solveH(EN_Project *p)
 
         /* Solve for hydraulics & advance to next time period */
         tstep = 0;
-        ERRCODE(EN_runH(p, &t));
-        ERRCODE(EN_nextH(p, &tstep));
+        ERRCODE(EN_runH(ph, &t));
+        ERRCODE(EN_nextH(ph, &tstep));
         /*** Updated 6/24/02 ***/
         writecon("\b\b\b\b\b\b\b\b\b\b");
       } while (tstep > 0);
@@ -833,12 +865,13 @@ int DLLEXPORT EN_solveH(EN_Project *p)
   /*** Updated 6/24/02 ***/
   writecon("\b\b\b\b\b\b\b\b                     ");
 
-  EN_closeH(p);
+  EN_closeH(ph);
   errcode = MAX(errcode, p->Warnflag);
-  return (errcode);
+
+  return set_error(p->error_handle, errcode);
 }
 
-int DLLEXPORT EN_saveH(EN_Project *p)
+int DLLEXPORT EN_saveH(EN_ProjectHandle ph)
 /*----------------------------------------------------------------
  **  Input:   none
  **  Output:  none
@@ -853,9 +886,11 @@ int DLLEXPORT EN_saveH(EN_Project *p)
   char tmpflag;
   int errcode;
 
+  EN_Project *p = (EN_Project*)ph;
+
   /* Check if hydraulic results exist */
   if (!p->save_options.SaveHflag)
-    return (104);
+    return set_error(p->error_handle, 104);
 
   /* Temporarily turn off WQ analysis */
   tmpflag = p->quality.Qualflag;
@@ -871,10 +906,10 @@ int DLLEXPORT EN_saveH(EN_Project *p)
   if (errcode) {
     errmsg(p, errcode);
   }
-  return (errcode);
+  return set_error(p->error_handle, errcode);
 }
 
-int DLLEXPORT EN_openH(EN_Project *p)
+int DLLEXPORT EN_openH(EN_ProjectHandle ph)
 /*----------------------------------------------------------------
  **  Input:   none
  **  Output:  none
@@ -885,16 +920,18 @@ int DLLEXPORT EN_openH(EN_Project *p)
 {
   int errcode = 0;
 
+  EN_Project *p = (EN_Project*)ph;
+
   /* Check that input data exists */
   p->hydraulics.OpenHflag = FALSE;
   p->save_options.SaveHflag = FALSE;
   if (!p->Openflag) {
-    return (102);
+    return set_error(p->error_handle, 102);
   }
 
   /* Check that previously saved hydraulics file not in use */
   if (p->out_files.Hydflag == USE) {
-    return (107);
+    return set_error(p->error_handle, 107);
   }
 
   /* Open hydraulics solver */
@@ -903,11 +940,12 @@ int DLLEXPORT EN_openH(EN_Project *p)
     p->hydraulics.OpenHflag = TRUE;
   else
     errmsg(p, errcode);
-  return (errcode);
+
+  return set_error(p->error_handle, errcode);
 }
 
 /*** Updated 3/1/01 ***/
-int DLLEXPORT EN_initH(EN_Project *p, int flag)
+int DLLEXPORT EN_initH(EN_ProjectHandle ph, int flag)
 /*----------------------------------------------------------------
  **  Input:   flag = 2-digit flag where 1st (left) digit indicates
  **                  if link flows should be re-initialized (1) or
@@ -922,6 +960,8 @@ int DLLEXPORT EN_initH(EN_Project *p, int flag)
   int errcode = 0;
   int sflag, fflag;
 
+  EN_Project *p = (EN_Project*)ph;
+
   /* Reset status flags */
   p->save_options.SaveHflag = FALSE;
   p->Warnflag = FALSE;
@@ -932,7 +972,7 @@ int DLLEXPORT EN_initH(EN_Project *p, int flag)
 
   /* Check that hydraulics solver was opened */
   if (!p->hydraulics.OpenHflag)
-    return (103);
+    return set_error(p->error_handle, 103);
 
   /* Open hydraulics file */
   p->save_options.Saveflag = FALSE;
@@ -942,7 +982,7 @@ int DLLEXPORT EN_initH(EN_Project *p, int flag)
       p->save_options.Saveflag = TRUE;
     else {
       errmsg(p, errcode);
-      return errcode;
+      return set_error(p->error_handle, errcode);
       }
   }
 
@@ -950,57 +990,67 @@ int DLLEXPORT EN_initH(EN_Project *p, int flag)
   inithyd(p, fflag);
   if (p->report.Statflag > 0)
     writeheader(p, STATHDR, 0);
-  return (errcode);
+  return set_error(p->error_handle, errcode);
 }
 
-int DLLEXPORT EN_runH(EN_Project *p, long *t) {
+int DLLEXPORT EN_runH(EN_ProjectHandle ph, long *t) {
   int errcode;
+
+  EN_Project *p = (EN_Project*)ph;
+
   *t = 0;
   if (!p->hydraulics.OpenHflag)
-    return (103);
+    return set_error(p->error_handle, 103);
   errcode = runhyd(p, t);
   if (errcode)
     errmsg(p, errcode);
-  return (errcode);
+  return set_error(p->error_handle, errcode);
 }
 
-int DLLEXPORT EN_nextH(EN_Project *p, long *tstep) {
+int DLLEXPORT EN_nextH(EN_ProjectHandle ph, long *tstep) {
   int errcode;
+
+  EN_Project *p = (EN_Project*)ph;
+
   *tstep = 0;
   if (!p->hydraulics.OpenHflag)
-    return (103);
+    return set_error(p->error_handle, 103);
   errcode = nexthyd(p, tstep);
   if (errcode)
     errmsg(p, errcode);
   else if (p->save_options.Saveflag && *tstep == 0)
     p->save_options.SaveHflag = TRUE;
-  return (errcode);
+  return set_error(p->error_handle, errcode);
 }
 
-int DLLEXPORT EN_closeH(EN_Project *p)
+int DLLEXPORT EN_closeH(EN_ProjectHandle ph)
 {
+  EN_Project *p = (EN_Project*)ph;
+
   if (!p->Openflag) {
-    return (102);
+    return set_error(p->error_handle, 102);
   }
   if (p->hydraulics.OpenHflag) {
     closehyd(p);
   }
   p->hydraulics.OpenHflag = FALSE;
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_savehydfile(EN_Project *p, char *filename) {
+int DLLEXPORT EN_savehydfile(EN_ProjectHandle ph, char *filename) {
   FILE *f;
   int c;
   FILE *HydFile;
   
+  EN_Project *p = (EN_Project*)ph;
+
   /* Check that hydraulics results exist */
   if (p->out_files.HydFile == NULL || !p->save_options.SaveHflag)
-    return (104);
+    return set_error(p->error_handle, 104);
 
   /* Open file */
   if ((f = fopen(filename, "w+b")) == NULL)
-    return (305);
+    return set_error(p->error_handle, 305);
 
   /* Copy from HydFile to f */
   HydFile = p->out_files.HydFile;
@@ -1009,17 +1059,19 @@ int DLLEXPORT EN_savehydfile(EN_Project *p, char *filename) {
     fputc(c, f);
   }
   fclose(f);
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_usehydfile(EN_Project *p, char *filename) {
+int DLLEXPORT EN_usehydfile(EN_ProjectHandle ph, char *filename) {
   int errcode;
 
+  EN_Project *p = (EN_Project*)ph;
+
   /* Check that input data exists & hydraulics system closed */
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (p->hydraulics.OpenHflag)
-    return (108);
+    return set_error(p->error_handle, 108);
 
   /* Try to open hydraulics file */
   strncpy(p->out_files.HydFname, filename, MAXFNAME);
@@ -1033,7 +1085,7 @@ int DLLEXPORT EN_usehydfile(EN_Project *p, char *filename) {
     p->out_files.Hydflag = SCRATCH;
     p->save_options.SaveHflag = FALSE;
   }
-  return (errcode);
+  return set_error(p->error_handle, errcode);
 }
 
 /*
@@ -1042,15 +1094,17 @@ int DLLEXPORT EN_usehydfile(EN_Project *p, char *filename) {
  ----------------------------------------------------------------
  */
 
-int DLLEXPORT EN_solveQ(EN_Project *p) {
+int DLLEXPORT EN_solveQ(EN_ProjectHandle ph) {
   int errcode;
   long t, tstep;
 
+  EN_Project *p = (EN_Project*)ph;
+
   /* Open WQ solver */
-  errcode = EN_openQ(p);
+  errcode = EN_openQ(ph);
   if (!errcode) {
     /* Initialize WQ */
-    errcode = EN_initQ(p, EN_SAVE);
+    errcode = EN_initQ(ph, EN_SAVE);
     if (p->quality.Qualflag)
       writecon(FMT15);
     else {
@@ -1076,8 +1130,8 @@ int DLLEXPORT EN_solveQ(EN_Project *p) {
 
         /* Retrieve current network solution & update WQ to next time period */
         tstep = 0;
-        ERRCODE(EN_runQ(p, &t));
-        ERRCODE(EN_nextQ(p, &tstep));
+        ERRCODE(EN_runQ(ph, &t));
+        ERRCODE(EN_nextQ(ph, &tstep));
 
         /*** Updated 6/24/02 ***/
         writecon("\b\b\b\b\b\b\b\b\b\b");
@@ -1089,18 +1143,20 @@ int DLLEXPORT EN_solveQ(EN_Project *p) {
 
   /*** Updated 6/24/02 ***/
   writecon("\b\b\b\b\b\b\b\b                     ");
-  EN_closeQ(p);
-  return (errcode);
+  EN_closeQ(ph);
+  return set_error(p->error_handle, errcode);
 }
 
-int DLLEXPORT EN_openQ(EN_Project *p) {
+int DLLEXPORT EN_openQ(EN_ProjectHandle ph) {
   int errcode = 0;
 
+  EN_Project *p = (EN_Project*)ph;
+
   /* Check that hydraulics results exist */
   p->quality.OpenQflag = FALSE;
   p->save_options.SaveQflag = FALSE;
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   // !LT! todo - check for p->save_options.SaveHflag / set sequential/step mode
   // if (!p->save_options.SaveHflag) return(104);
 
@@ -1110,13 +1166,16 @@ int DLLEXPORT EN_openQ(EN_Project *p) {
     p->quality.OpenQflag = TRUE;
   else
     errmsg(p, errcode);
-  return (errcode);
+  return set_error(p->error_handle, errcode);
 }
 
-int DLLEXPORT EN_initQ(EN_Project *p, int saveflag) {
+int DLLEXPORT EN_initQ(EN_ProjectHandle ph, int saveflag) {
   int errcode = 0;
+
+  EN_Project *p = (EN_Project*)ph;
+
   if (!p->quality.OpenQflag)
-    return (105);
+    return set_error(p->error_handle, 105);
   initqual(p);
   p->save_options.SaveQflag = FALSE;
   p->save_options.Saveflag = FALSE;
@@ -1125,56 +1184,66 @@ int DLLEXPORT EN_initQ(EN_Project *p, int saveflag) {
     if (!errcode)
       p->save_options.Saveflag = TRUE;
   }
-  return (errcode);
+  return set_error(p->error_handle, errcode);
 }
 
-int DLLEXPORT EN_runQ(EN_Project *p, long *t) {
+int DLLEXPORT EN_runQ(EN_ProjectHandle ph, long *t) {
   int errcode;
+
+  EN_Project *p = (EN_Project*)ph;
+
   *t = 0;
   if (!p->quality.OpenQflag)
-    return (105);
+    return set_error(p->error_handle, 105);
   errcode = runqual(p, t);
   if (errcode)
     errmsg(p, errcode);
-  return (errcode);
+  return set_error(p->error_handle, errcode);
 }
 
-int DLLEXPORT EN_nextQ(EN_Project *p, long *tstep) {
+int DLLEXPORT EN_nextQ(EN_ProjectHandle ph, long *tstep) {
   int errcode;
+
+  EN_Project *p = (EN_Project*)ph;
+
   *tstep = 0;
   if (!p->quality.OpenQflag)
-    return (105);
+    return set_error(p->error_handle, 105);
   errcode = nextqual(p, tstep);
   if (!errcode && p->save_options.Saveflag && *tstep == 0) {
     p->save_options.SaveQflag = TRUE;
   }
   if (errcode)
     errmsg(p, errcode);
-  return (errcode);
+  return set_error(p->error_handle, errcode);
 }
 
-int DLLEXPORT EN_stepQ(EN_Project *p, long *tleft) {
+int DLLEXPORT EN_stepQ(EN_ProjectHandle ph, long *tleft) {
   int errcode;
+
+  EN_Project *p = (EN_Project*)ph;
+
   *tleft = 0;
   if (!p->quality.OpenQflag)
-    return (105);
+    return set_error(p->error_handle, 105);
   errcode = stepqual(p, tleft);
   if (!errcode && p->save_options.Saveflag && *tleft == 0) {
     p->save_options.SaveQflag = TRUE;
   }
   if (errcode)
     errmsg(p, errcode);
-  return (errcode);
+  return set_error(p->error_handle, errcode);
 }
 
-int DLLEXPORT EN_closeQ(EN_Project *p)
+int DLLEXPORT EN_closeQ(EN_ProjectHandle ph) {
+
+  EN_Project *p = (EN_Project*)ph;
 
-{
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   closequal(p);
   p->quality.OpenQflag = FALSE;
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
 /*
@@ -1183,48 +1252,59 @@ int DLLEXPORT EN_closeQ(EN_Project *p)
  ----------------------------------------------------------------
  */
 
-int DLLEXPORT EN_writeline(EN_Project *p, char *line) {
+int DLLEXPORT EN_writeline(EN_ProjectHandle ph, char *line) {
+
+  EN_Project *p = (EN_Project*)ph;
+
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   writeline(p, line);
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_report(EN_Project *p) {
+int DLLEXPORT EN_report(EN_ProjectHandle ph) {
   int errcode;
 
+  EN_Project *p = (EN_Project*)ph;
+
   /* Check if results saved to binary output file */
   if (!p->save_options.SaveQflag)
-    return (106);
+    return set_error(p->error_handle, 106);
   errcode = writereport(p);
   if (errcode)
     errmsg(p, errcode);
-  return (errcode);
+  return set_error(p->error_handle, errcode);
 }
 
-int DLLEXPORT EN_resetreport(EN_Project *p) {
+int DLLEXPORT EN_resetreport(EN_ProjectHandle ph) {
   int i;
+
+  EN_Project *p = (EN_Project*)ph;
+
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   initreport(&p->report);
   for (i = 1; i <= p->network.Nnodes; i++)
     p->network.Node[i].Rpt = 0;
   for (i = 1; i <= p->network.Nlinks; i++)
     p->network.Link[i].Rpt = 0;
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_setreport(EN_Project *p, char *s) {
+int DLLEXPORT EN_setreport(EN_ProjectHandle ph, char *s) {
   char s1[MAXLINE + 1];
+
+  EN_Project *p = (EN_Project*)ph;
+
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (strlen(s) > MAXLINE)
-    return (250);
+    return set_error(p->error_handle, 250);
   strcpy(s1, s);
   if (setreport(p, s1) > 0)
-    return (250);
+    return set_error(p->error_handle, 250);
   else
-    return (0);
+    return set_error(p->error_handle, 0);
 }
 
 /*
@@ -1247,14 +1327,16 @@ int DLLEXPORT EN_getversion(int *v)
  */
 {
   *v = CODEVERSION;
-  return (0);
+  return 0;
 }
 
-int DLLEXPORT EN_getcontrol(EN_Project *pr, int cindex, int *ctype, int *lindex,
+int DLLEXPORT EN_getcontrol(EN_ProjectHandle ph, int cindex, int *ctype, int *lindex,
                             EN_API_FLOAT_TYPE *setting, int *nindex,
                             EN_API_FLOAT_TYPE *level) {
   double s, lvl;
 
+  EN_Project *pr = (EN_Project*)ph;
+
   EN_Network *net = &pr->network;
 
   Scontrol *Control = net->Control;
@@ -1263,16 +1345,16 @@ int DLLEXPORT EN_getcontrol(EN_Project *pr, int cindex, int *ctype, int *lindex,
 
   const int Njuncs = net->Njuncs;
   double *Ucf = pr->Ucf;
-
+  
   s = 0.0;
   lvl = 0.0;
   *ctype = 0;
   *lindex = 0;
   *nindex = 0;
   if (!pr->Openflag)
-    return (102);
+    return set_error(pr->error_handle, 102);
   if (cindex < 1 || cindex > net->Ncontrols)
-    return (241);
+    return set_error(pr->error_handle, 241);
   *ctype = Control[cindex].Type;
   *lindex = Control[cindex].Link;
   s = Control[cindex].Setting;
@@ -1305,15 +1387,18 @@ int DLLEXPORT EN_getcontrol(EN_Project *pr, int cindex, int *ctype, int *lindex,
     lvl = (EN_API_FLOAT_TYPE)Control[cindex].Time;
   *setting = (EN_API_FLOAT_TYPE)s;
   *level = (EN_API_FLOAT_TYPE)lvl;
-  return (0);
+  return set_error(pr->error_handle, 0);
 }
 
-int DLLEXPORT EN_getcount(EN_Project *pr, EN_CountType code, int *count) {
+int DLLEXPORT EN_getcount(EN_ProjectHandle ph, EN_CountType code, int *count) {
+
+  EN_Project *pr = (EN_Project*)ph;
+
   EN_Network *net = &pr->network;
 
   *count = 0;
   if (!pr->Openflag)
-    return (102);
+    return set_error(pr->error_handle, 102);
   switch (code) {
   case EN_NODECOUNT:
     *count = net->Nnodes;
@@ -1337,13 +1422,16 @@ int DLLEXPORT EN_getcount(EN_Project *pr, EN_CountType code, int *count) {
     *count = net->Nrules;
     break;
   default:
-    return (251);
+    return set_error(pr->error_handle, 251);
   }
-  return (0);
+  return set_error(pr->error_handle, 0);
 }
 
-int DLLEXPORT EN_getoption(EN_Project *pr, EN_Option code,
+int DLLEXPORT EN_getoption(EN_ProjectHandle ph, EN_Option code,
                            EN_API_FLOAT_TYPE *value) {
+
+  EN_Project *pr = (EN_Project*)ph;
+
   hydraulics_t *hyd = &pr->hydraulics;
   quality_t *qu = &pr->quality;
   double *Ucf = pr->Ucf;
@@ -1351,7 +1439,7 @@ int DLLEXPORT EN_getoption(EN_Project *pr, EN_Option code,
   double v = 0.0;
   *value = 0.0;
   if (!pr->Openflag)
-    return (102);
+    return set_error(pr->error_handle, 102);
   switch (code) {
   case EN_TRIALS:
     v = (double)hyd->MaxIter;
@@ -1378,15 +1466,17 @@ int DLLEXPORT EN_getoption(EN_Project *pr, EN_Option code,
     break;
 
   default:
-    return (251);
+    return set_error(pr->error_handle, 251);
   }
   *value = (EN_API_FLOAT_TYPE)v;
-  return (0);
+  return set_error(pr->error_handle, 0);
 }
 
-int DLLEXPORT EN_gettimeparam(EN_Project *pr, int code, long *value) {
-
+int DLLEXPORT EN_gettimeparam(EN_ProjectHandle ph, int code, long *value) {
   int i;
+
+  EN_Project *pr = (EN_Project*)ph;
+
   report_options_t *rep = &pr->report;
   quality_t *qu = &pr->quality;
   time_options_t *time = &pr->time_options;
@@ -1394,9 +1484,9 @@ int DLLEXPORT EN_gettimeparam(EN_Project *pr, int code, long *value) {
 
   *value = 0;
   if (!pr->Openflag)
-    return (102);
+    return set_error(pr->error_handle, 102);
   if (code < EN_DURATION || code > EN_NEXTEVENTIDX)
-    return (251);
+    return set_error(pr->error_handle, 251);
   switch (code) {
   case EN_DURATION:
     *value = time->Dur;
@@ -1445,25 +1535,31 @@ int DLLEXPORT EN_gettimeparam(EN_Project *pr, int code, long *value) {
       *value = i;
       break;
   }
-  return (0);
+  return set_error(pr->error_handle, 0);
 }
 
-int DLLEXPORT EN_getflowunits(EN_Project *p, int *code) {
+int DLLEXPORT EN_getflowunits(EN_ProjectHandle ph, int *code) {
+
+  EN_Project *p = (EN_Project*)ph;
+
   *code = -1;
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   *code = p->parser.Flowflag;
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_setflowunits(EN_Project *p, int code) {
+int DLLEXPORT EN_setflowunits(EN_ProjectHandle ph, int code) {
   int i, j;
   double qfactor, vfactor, hfactor, efactor, xfactor, yfactor;
+
+  EN_Project *p = (EN_Project*)ph;
+
   double *Ucf = p->Ucf;
   EN_Network *net = &p->network;
   
   if (!p->Openflag) { 
-    return(102);
+    return set_error(p->error_handle, 102);
   }
   
   /* Determine unit system based on flow units */
@@ -1527,141 +1623,179 @@ int DLLEXPORT EN_setflowunits(EN_Project *p, int code) {
     }
   }
   
-  return(0);
+  return set_error(p->error_handle, 0);
 }
 
-
-int DLLEXPORT EN_getdemandmodel(EN_Project *p, int *type, EN_API_FLOAT_TYPE *pmin,
+int DLLEXPORT EN_getdemandmodel(EN_ProjectHandle ph, int *type, EN_API_FLOAT_TYPE *pmin,
               EN_API_FLOAT_TYPE *preq, EN_API_FLOAT_TYPE *pexp)
 {
+    EN_Project *p = (EN_Project*)ph;
+
     *type = p->hydraulics.DemandModel;
     *pmin = (EN_API_FLOAT_TYPE)(p->hydraulics.Pmin * p->Ucf[PRESSURE]);
     *preq = (EN_API_FLOAT_TYPE)(p->hydraulics.Preq * p->Ucf[PRESSURE]);
     *pexp = (EN_API_FLOAT_TYPE)(p->hydraulics.Pexp);
-    return 0;
+
+	return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_setdemandmodel(EN_Project *p, int type, EN_API_FLOAT_TYPE pmin,
+int DLLEXPORT EN_setdemandmodel(EN_ProjectHandle ph, int type, EN_API_FLOAT_TYPE pmin,
               EN_API_FLOAT_TYPE preq, EN_API_FLOAT_TYPE pexp)
 {
-    if (type < 0 || type > EN_PDA) return 251;
-    if (pmin > preq || pexp <= 0.0) return 202;
+    EN_Project *p = (EN_Project*)ph;
+
+    if (type < 0 || type > EN_PDA) return set_error(p->error_handle, 251);
+    if (pmin > preq || pexp <= 0.0) return set_error(p->error_handle, 202);
     p->hydraulics.DemandModel = type;
     p->hydraulics.Pmin = pmin / p->Ucf[PRESSURE];
     p->hydraulics.Preq = preq / p->Ucf[PRESSURE];
     p->hydraulics.Pexp = pexp;
-    return 0;
+
+    return set_error(p->error_handle, 0);
 }
 
 
-int DLLEXPORT EN_getpatternindex(EN_Project *p, char *id, int *index) {
+int DLLEXPORT EN_getpatternindex(EN_ProjectHandle ph, char *id, int *index) {
   int i;
+
+  EN_Project *p = (EN_Project*)ph;
+
   *index = 0;
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   for (i = 1; i <= p->network.Npats; i++) {
     if (strcmp(id, p->network.Pattern[i].ID) == 0) {
       *index = i;
-      return (0);
+      return set_error(p->error_handle, 0);
     }
   }
   *index = 0;
-  return (205);
+  return set_error(p->error_handle, 205);
 }
 
-int DLLEXPORT EN_getpatternid(EN_Project *p, int index, char *id) {
+int DLLEXPORT EN_getpatternid(EN_ProjectHandle ph, int index, char *id) {
+
+  EN_Project *p = (EN_Project*)ph;
+
   strcpy(id, "");
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index < 1 || index > p->network.Npats)
-    return (205);
+    return set_error(p->error_handle, 205);
   strcpy(id, p->network.Pattern[index].ID);
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_getpatternlen(EN_Project *p, int index, int *len) {
+int DLLEXPORT EN_getpatternlen(EN_ProjectHandle ph, int index, int *len) {
+
+  EN_Project *p = (EN_Project*)ph;
+
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index < 1 || index > p->network.Npats)
-    return (205);
+    return set_error(p->error_handle, 205);
   *len = p->network.Pattern[index].Length;
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_getpatternvalue(EN_Project *p, int index, int period,
+int DLLEXPORT EN_getpatternvalue(EN_ProjectHandle ph, int index, int period,
                                  EN_API_FLOAT_TYPE *value) {
+
+  EN_Project *p = (EN_Project*)ph;
+
   *value = 0.0;
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index < 1 || index > p->network.Npats)
-    return (205);
+    return set_error(p->error_handle, 205);
   if (period < 1 || period > p->network.Pattern[index].Length)
-    return (251);
+    return set_error(p->error_handle, 251);
   *value = (EN_API_FLOAT_TYPE)p->network.Pattern[index].F[period - 1];
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_getcurveindex(EN_Project *p, char *id, int *index) {
+int DLLEXPORT EN_getcurveindex(EN_ProjectHandle ph, char *id, int *index) {
   int i;
+
+  EN_Project *p = (EN_Project*)ph;
+
   *index = 0;
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   for (i = 1; i <= p->network.Ncurves; i++) {
     if (strcmp(id, p->network.Curve[i].ID) == 0) {
       *index = i;
-      return (0);
+      return set_error(p->error_handle, 0);
     }
   }
   *index = 0;
-  return (206);
+  return set_error(p->error_handle, 206);
 }
 
-int DLLEXPORT EN_getcurveid(EN_Project *p, int index, char *id) {
+int DLLEXPORT EN_getcurveid(EN_ProjectHandle ph, int index, char *id) {
+
+  EN_Project *p = (EN_Project*)ph;
+
   strcpy(id, "");
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index < 1 || index > p->network.Ncurves)
-    return (206);
+    return set_error(p->error_handle, 206);
   strcpy(id, p->network.Curve[index].ID);
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_getcurvelen(EN_Project *p, int index, int *len) {
+int DLLEXPORT EN_getcurvelen(EN_ProjectHandle ph, int index, int *len) {
+
+  EN_Project *p = (EN_Project*)ph;
+
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index < 1 || index > p->network.Ncurves)
-    return (206);
+    return set_error(p->error_handle, 206);
   *len = p->network.Curve[index].Npts;
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_getcurvevalue(EN_Project *p, int index, int pnt,
+int DLLEXPORT EN_getcurvevalue(EN_ProjectHandle ph, int index, int pnt,
                                EN_API_FLOAT_TYPE *x, EN_API_FLOAT_TYPE *y) {
+
+  EN_Project *p = (EN_Project*)ph;
+
   *x = 0.0;
   *y = 0.0;
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index < 1 || index > p->network.Ncurves)
-    return (206);
+    return set_error(p->error_handle, 206);
   if (pnt < 1 || pnt > p->network.Curve[index].Npts)
-    return (251);
+    return set_error(p->error_handle, 251);
   *x = (EN_API_FLOAT_TYPE)p->network.Curve[index].X[pnt - 1];
   *y = (EN_API_FLOAT_TYPE)p->network.Curve[index].Y[pnt - 1];
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_getqualtype(EN_Project *p, int *qualcode, int *tracenode) {
+int DLLEXPORT EN_getqualtype(EN_ProjectHandle ph, int *qualcode, int *tracenode) {
+
+  EN_Project *p = (EN_Project*)ph;
+
   *tracenode = 0;
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   *qualcode = p->quality.Qualflag;
   if (p->quality.Qualflag == TRACE)
     *tracenode = p->quality.TraceNode;
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_getqualinfo(EN_Project *p, int *qualcode, char *chemname, char *chemunits, int *tracenode) {
-  EN_getqualtype(p, qualcode, tracenode);
+
+int DLLEXPORT EN_getqualinfo(EN_ProjectHandle ph, int *qualcode, char *chemname,
+                             char *chemunits, int *tracenode) {
+
+  EN_Project *p = (EN_Project*)ph;
+
+  EN_getqualtype(ph, qualcode, tracenode);
+
   if (p->quality.Qualflag == TRACE) {
     strncpy(chemname, "", MAXID);
     strncpy(chemunits, "dimensionless", MAXID);
@@ -1669,10 +1803,68 @@ int DLLEXPORT EN_getqualinfo(EN_Project *p, int *qualcode, char *chemname, char
     strncpy(chemname, p->quality.ChemName, MAXID);
     strncpy(chemunits, p->quality.ChemUnits, MAXID);
   }
-  return 0;
+  return set_error(p->error_handle, 0);
+}
+
+void errorLookup(int errcode, char *dest_msg, int dest_len)
+// Purpose: takes error code returns error message
+{
+    char *msg = NULL;
+
+    switch (errcode)
+    {
+    case 1: msg = WARN1;
+    break;
+    case 2: msg = WARN2;
+    break;
+    case 3: msg = WARN3;
+    break;
+    case 4: msg = WARN4;
+    break;
+    case 5: msg = WARN5;
+    break;
+    case 6: msg = WARN6;
+    break;
+    default:
+        msg = geterrmsg(errcode, msg);
+    }
+    strncpy(dest_msg, msg, MAXMSG);
+}
+
+void DLLEXPORT EN_clearError(EN_ProjectHandle ph)
+{
+    EN_Project *p = (EN_Project*)ph;
+
+    clear_error(p->error_handle);
+}
+
+int DLLEXPORT EN_checkError(EN_ProjectHandle ph, char** msg_buffer)
+//
+// Purpose: Returns the error message or NULL.
+//
+// Note: Caller must free memory allocated by EN_check_error
+//
+{
+    int errorcode = 0;
+    char *temp = NULL;
+    EN_Project *p = (EN_Project*)ph;
+
+
+    if (p == NULL) return -1;
+    else
+    {
+        errorcode = p->error_handle->error_status;
+        if (errorcode)
+            temp = check_error(p->error_handle);
+
+        *msg_buffer = temp;
+    }
+
+    return errorcode;
 }
 
 int DLLEXPORT EN_geterror(int errcode, char *errmsg, int n) {
+	// Deprecate? 
   char newMsg[MAXMSG+1];
   
   switch (errcode) {
@@ -1699,12 +1891,15 @@ int DLLEXPORT EN_geterror(int errcode, char *errmsg, int n) {
     strncpy(errmsg, newMsg, n);
   }
   if (strlen(errmsg) == 0)
-    return (251);
+    return 251;
   else
-    return (0);
+    return 0;
 }
 
-int DLLEXPORT EN_getstatistic(EN_Project *p, int code, EN_API_FLOAT_TYPE *value) {
+int DLLEXPORT EN_getstatistic(EN_ProjectHandle ph, int code, EN_API_FLOAT_TYPE *value) {
+
+  EN_Project *p = (EN_Project*)ph;
+
   switch (code) {
   case EN_ITERATIONS:
     *value = (EN_API_FLOAT_TYPE)p->hydraulics.Iterations;
@@ -1721,7 +1916,7 @@ int DLLEXPORT EN_getstatistic(EN_Project *p, int code, EN_API_FLOAT_TYPE *value)
   default:
     break;
   }
-  return 0;
+  return set_error(p->error_handle, 0);
 }
 
 /*
@@ -1730,33 +1925,42 @@ int DLLEXPORT EN_getstatistic(EN_Project *p, int code, EN_API_FLOAT_TYPE *value)
  ----------------------------------------------------------------
  */
 
-int DLLEXPORT EN_getnodeindex(EN_Project *p, char *id, int *index) {
+int DLLEXPORT EN_getnodeindex(EN_ProjectHandle ph, char *id, int *index) {
+
+  EN_Project *p = (EN_Project*)ph;
+
   *index = 0;
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   *index = findnode(&p->network,id);
   if (*index == 0)
-    return (203);
+    return set_error(p->error_handle, 203);
   else
-    return (0);
+    return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_getnodeid(EN_Project *p, int index, char *id) {
+int DLLEXPORT EN_getnodeid(EN_ProjectHandle ph, int index, char *id) {
+
+  EN_Project *p = (EN_Project*)ph;
+
   strcpy(id, "");
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index < 1 || index > p->network.Nnodes)
-    return (203);
+    return set_error(p->error_handle, 203);
   strcpy(id, p->network.Node[index].ID);
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_getnodetype(EN_Project *p, int index, int *code) {
+int DLLEXPORT EN_getnodetype(EN_ProjectHandle ph, int index, int *code) {
+
+  EN_Project *p = (EN_Project*)ph;
+
   *code = -1;
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index < 1 || index > p->network.Nnodes)
-    return (203);
+    return set_error(p->error_handle, 203);
   if (index <= p->network.Njuncs)
     *code = EN_JUNCTION;
   else {
@@ -1765,48 +1969,56 @@ int DLLEXPORT EN_getnodetype(EN_Project *p, int index, int *code) {
     else
       *code = EN_TANK;
   }
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_getcoord(EN_Project *p, int index, EN_API_FLOAT_TYPE *x,
+int DLLEXPORT EN_getcoord(EN_ProjectHandle ph, int index, EN_API_FLOAT_TYPE *x,
                           EN_API_FLOAT_TYPE *y) {
+
+  EN_Project *p = (EN_Project*)ph;
+
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index < 1 || index > p->network.Nnodes)
-    return (203);
+    return set_error(p->error_handle, 203);
   if (!p->parser.Coordflag)
-    return (255);
+    return set_error(p->error_handle, 255);
 
   // check if node have coords
   if (p->network.Coord[index].HaveCoords == FALSE)
-    return (254);
+    return set_error(p->error_handle, 254);
 
   *x = (EN_API_FLOAT_TYPE)p->network.Coord[index].X;
   *y = (EN_API_FLOAT_TYPE)p->network.Coord[index].Y;
-  return 0;
+
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_setcoord(EN_Project *p, int index, EN_API_FLOAT_TYPE x,
+int DLLEXPORT EN_setcoord(EN_ProjectHandle ph, int index, EN_API_FLOAT_TYPE x,
                           EN_API_FLOAT_TYPE y) {
+
+  EN_Project *p = (EN_Project*)ph;
+
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index < 1 || index > p->network.Nnodes)
-    return (203);
+    return set_error(p->error_handle, 203);
   if (!p->parser.Coordflag)
-    return (255);
+    return set_error(p->error_handle, 255);
 
   p->network.Coord[index].X = x;
   p->network.Coord[index].Y = y;
   p->network.Coord[index].HaveCoords = TRUE;
-  return 0;
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_getnodevalue(EN_Project *p, int index, int code,
+int DLLEXPORT EN_getnodevalue(EN_ProjectHandle ph, int index, int code,
                               EN_API_FLOAT_TYPE *value) {
   double v = 0.0;
   Pdemand demand;
   Psource source;
 
+  EN_Project *p = (EN_Project*)ph;
   
   EN_Network *net = &p->network;
   hydraulics_t *hyd = &p->hydraulics;
@@ -1826,9 +2038,9 @@ int DLLEXPORT EN_getnodevalue(EN_Project *p, int index, int code,
   /* Check for valid arguments */
   *value = 0.0;
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index <= 0 || index > Nnodes)
-    return (203);
+    return set_error(p->error_handle, 203);
 
   /* Retrieve called-for parameter */
   switch (code) {
@@ -1872,7 +2084,7 @@ int DLLEXPORT EN_getnodevalue(EN_Project *p, int index, int code,
   case EN_SOURCEPAT:
     source = Node[index].S;
     if (source == NULL)
-      return (240);
+      return set_error(p->error_handle, 240);
     if (code == EN_SOURCEQUAL)
       v = source->C0;
     else if (code == EN_SOURCEMASS)
@@ -1885,7 +2097,7 @@ int DLLEXPORT EN_getnodevalue(EN_Project *p, int index, int code,
 
   case EN_TANKLEVEL:
     if (index <= Njuncs)
-      return (251);
+      return set_error(p->error_handle, 251);
     v = (Tank[index - Njuncs].H0 - Node[index].El) * Ucf[ELEV];
     break;
 
@@ -1986,15 +2198,15 @@ int DLLEXPORT EN_getnodevalue(EN_Project *p, int index, int code,
 
   case EN_TANKVOLUME:
     if (index <= Njuncs)
-      return (251);
+      return set_error(p->error_handle, 251);
     v = tankvolume(p, index - Njuncs, hyd->NodeHead[index]) * Ucf[VOLUME];
     break;
 
   default:
-    return (251);
+    return set_error(p->error_handle, 251);
   }
   *value = (EN_API_FLOAT_TYPE)v;
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
 /*
@@ -2003,55 +2215,70 @@ int DLLEXPORT EN_getnodevalue(EN_Project *p, int index, int code,
  ----------------------------------------------------------------
  */
 
-int DLLEXPORT EN_getlinkindex(EN_Project *p, char *id, int *index) {
+int DLLEXPORT EN_getlinkindex(EN_ProjectHandle ph, char *id, int *index) {
+
+  EN_Project *p = (EN_Project*)ph;
+
   *index = 0;
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   *index = findlink(&p->network,id);
   if (*index == 0)
-    return (204);
+    return set_error(p->error_handle, 204);
   else
-    return (0);
+    return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_getlinkid(EN_Project *p, int index, char *id) {
+int DLLEXPORT EN_getlinkid(EN_ProjectHandle ph, int index, char *id) {
+
+  EN_Project *p = (EN_Project*)ph;
+
   strcpy(id, "");
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index < 1 || index > p->network.Nlinks)
-    return (204);
+    return set_error(p->error_handle, 204);
   strcpy(id, p->network.Link[index].ID);
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_getlinktype(EN_Project *p, int index, EN_LinkType *code) {
+int DLLEXPORT EN_getlinktype(EN_ProjectHandle ph, int index, EN_LinkType *code) {
+
+  EN_Project *p = (EN_Project*)ph;
+
   *code = -1;
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index < 1 || index > p->network.Nlinks)
-    return (204);
+    return set_error(p->error_handle, 204);
   *code = p->network.Link[index].Type;
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_getlinknodes(EN_Project *p, int index, int *node1,
+int DLLEXPORT EN_getlinknodes(EN_ProjectHandle ph, int index, int *node1,
                               int *node2) {
+
+  EN_Project *p = (EN_Project*)ph;
+
   *node1 = 0;
   *node2 = 0;
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index < 1 || index > p->network.Nlinks)
-    return (204);
+    return set_error(p->error_handle, 204);
   *node1 = p->network.Link[index].N1;
   *node2 = p->network.Link[index].N2;
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_getlinkvalue(EN_Project *p, int index, EN_LinkProperty code, EN_API_FLOAT_TYPE *value) {
+int DLLEXPORT EN_getlinkvalue(EN_ProjectHandle ph, int index, EN_LinkProperty code,
+                                                        EN_API_FLOAT_TYPE *value) {
   double a, h, q, v = 0.0;
   int returnValue = 0;
   int pmp;
   
+  EN_Project *p = (EN_Project*)ph;
+
   EN_Network *net = &p->network;
   hydraulics_t *hyd = &p->hydraulics;
   
@@ -2067,9 +2294,9 @@ int DLLEXPORT EN_getlinkvalue(EN_Project *p, int index, EN_LinkProperty code, EN
   /* Check for valid arguments */
   *value = 0.0;
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index <= 0 || index > Nlinks)
-    return (204);
+    return set_error(p->error_handle, 204);
 
   /* Retrieve called-for parameter */
   switch (code) {
@@ -2111,7 +2338,7 @@ int DLLEXPORT EN_getlinkvalue(EN_Project *p, int index, EN_LinkProperty code, EN
       
     case EN_INITSETTING:
       if (Link[index].Type == EN_PIPE || Link[index].Type == EN_CVPIPE)
-        return (ENgetlinkvalue(index, EN_ROUGHNESS, value));
+        return set_error(p->error_handle, ENgetlinkvalue(index, EN_ROUGHNESS, value));
       v = Link[index].Kc;
       switch (Link[index].Type) {
         case EN_PRV:
@@ -2214,7 +2441,7 @@ int DLLEXPORT EN_getlinkvalue(EN_Project *p, int index, EN_LinkProperty code, EN
       
     case EN_SETTING:
       if (Link[index].Type == EN_PIPE || Link[index].Type == EN_CVPIPE) {
-        return (ENgetlinkvalue(index, EN_ROUGHNESS, value));
+        return set_error(p->error_handle, ENgetlinkvalue(index, EN_ROUGHNESS, value));
       }
       if (LinkSetting[index] == MISSING) {
         v = 0.0;
@@ -2286,19 +2513,21 @@ int DLLEXPORT EN_getlinkvalue(EN_Project *p, int index, EN_LinkProperty code, EN
       returnValue = 251;
   }
   *value = (EN_API_FLOAT_TYPE)v;
-  return returnValue;
+  return set_error(p->error_handle, returnValue);
 }
 
-int DLLEXPORT EN_getcurve(EN_Project *p, int curveIndex, char *id, int *nValues,
+int DLLEXPORT EN_getcurve(EN_ProjectHandle ph, int curveIndex, char *id, int *nValues,
                           EN_API_FLOAT_TYPE **xValues,
                           EN_API_FLOAT_TYPE **yValues) {
   int iPoint, nPoints;
   Scurve curve;
   EN_API_FLOAT_TYPE *pointX, *pointY;
 
+  EN_Project *p = (EN_Project*)ph;
+
   /* Check that input file opened */
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
 
   curve = p->network.Curve[curveIndex];
   nPoints = curve.Npts;
@@ -2319,7 +2548,7 @@ int DLLEXPORT EN_getcurve(EN_Project *p, int curveIndex, char *id, int *nValues,
   *xValues = pointX;
   *yValues = pointY;
 
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
 /*
@@ -2328,7 +2557,7 @@ int DLLEXPORT EN_getcurve(EN_Project *p, int curveIndex, char *id, int *nValues,
  ----------------------------------------------------------------
  */
 
-int DLLEXPORT EN_setcontrol(EN_Project *p, int cindex, int ctype, int lindex,
+int DLLEXPORT EN_setcontrol(EN_ProjectHandle ph, int cindex, int ctype, int lindex,
                             EN_API_FLOAT_TYPE setting, int nindex,
                             EN_API_FLOAT_TYPE level) {
   char status = ACTIVE;
@@ -2344,13 +2573,15 @@ int DLLEXPORT EN_setcontrol(EN_Project *p, int cindex, int ctype, int lindex,
   int Nlinks;
   double *Ucf;
 
+  EN_Project *p = (EN_Project*)ph;
+
   /* Check that input file opened */
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
 
   /* Check that control exists */
   if (cindex < 1 || cindex > p->network.Ncontrols)
-    return (241);
+    return set_error(p->error_handle, 241);
 
   
   net = &p->network;
@@ -2368,25 +2599,25 @@ int DLLEXPORT EN_setcontrol(EN_Project *p, int cindex, int ctype, int lindex,
   /* Check that controlled link exists */
   if (lindex == 0) {
     Control[cindex].Link = 0;
-    return (0);
+    return set_error(p->error_handle, 0);
   }
   if (lindex < 0 || lindex > Nlinks)
-    return (204);
+    return set_error(p->error_handle, 204);
 
   /* Cannot control check valve. */
   if (Link[lindex].Type == EN_CVPIPE)
-    return (207);
+    return set_error(p->error_handle, 207);
 
   /* Check for valid parameters */
   if (ctype < 0 || ctype > EN_TIMEOFDAY)
-    return (251);
+    return set_error(p->error_handle, 251);
   if (ctype == EN_LOWLEVEL || ctype == EN_HILEVEL) {
     if (nindex < 1 || nindex > Nnodes)
-      return (203);
+      return set_error(p->error_handle, 203);
   } else
     nindex = 0;
   if (s < 0.0 || lvl < 0.0)
-    return (202);
+    return set_error(p->error_handle, 202);
 
   /* Adjust units of control parameters */
   switch (Link[lindex].Type) {
@@ -2406,7 +2637,7 @@ int DLLEXPORT EN_setcontrol(EN_Project *p, int cindex, int ctype, int lindex,
       else if (s == 1.0)
         status = OPEN;
       else
-        return (202);
+        return set_error(p->error_handle, 202);
       s = Link[lindex].Kc;
       break;
       
@@ -2437,10 +2668,10 @@ int DLLEXPORT EN_setcontrol(EN_Project *p, int cindex, int ctype, int lindex,
   Control[cindex].Setting = s;
   Control[cindex].Grade = lvl;
   Control[cindex].Time = t;
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_setnodevalue(EN_Project *p, int index, int code, EN_API_FLOAT_TYPE v)
+int DLLEXPORT EN_setnodevalue(EN_ProjectHandle ph, int index, int code, EN_API_FLOAT_TYPE v)
 /*----------------------------------------------------------------
  **  Input:   index = node index
  **           code  = node parameter code (see EPANET2.H)
@@ -2451,6 +2682,8 @@ int DLLEXPORT EN_setnodevalue(EN_Project *p, int index, int code, EN_API_FLOAT_T
  **----------------------------------------------------------------
  */
 {
+  EN_Project *p = (EN_Project*)ph;
+
   EN_Network *net = &p->network;
   hydraulics_t *hyd = &p->hydraulics;
   quality_t *qu = &p->quality;
@@ -2471,9 +2704,9 @@ int DLLEXPORT EN_setnodevalue(EN_Project *p, int index, int code, EN_API_FLOAT_T
   double value = v;
 
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index <= 0 || index > Nnodes)
-    return (203);
+    return set_error(p->error_handle, 203);
   switch (code) {
   case EN_ELEVATION:
     if (index <= Njuncs)
@@ -2503,7 +2736,7 @@ int DLLEXPORT EN_setnodevalue(EN_Project *p, int index, int code, EN_API_FLOAT_T
     /* NOTE: primary demand category is last on demand list */
     j = ROUND(value);
     if (j < 0 || j > Npats)
-      return (205);
+      return set_error(p->error_handle, 205);
     if (index <= Njuncs) {
       for (demand = Node[index].D; demand != NULL; demand = demand->next) {
         if (demand->next == NULL)
@@ -2515,9 +2748,9 @@ int DLLEXPORT EN_setnodevalue(EN_Project *p, int index, int code, EN_API_FLOAT_T
 
   case EN_EMITTER:
     if (index > Njuncs)
-      return (203);
+      return set_error(p->error_handle, 203);
     if (value < 0.0)
-      return (202);
+      return set_error(p->error_handle, 202);
     if (value > 0.0)
       value = pow((Ucf[FLOW] / value), hyd->Qexp) / Ucf[PRESSURE];
     Node[index].Ke = value;
@@ -2525,7 +2758,7 @@ int DLLEXPORT EN_setnodevalue(EN_Project *p, int index, int code, EN_API_FLOAT_T
 
   case EN_INITQUAL:
     if (value < 0.0)
-      return (202);
+      return set_error(p->error_handle, 202);
     Node[index].C0 = value / Ucf[QUALITY];
     if (index > Njuncs)
       Tank[index - Njuncs].C = Node[index].C0;
@@ -2535,12 +2768,12 @@ int DLLEXPORT EN_setnodevalue(EN_Project *p, int index, int code, EN_API_FLOAT_T
   case EN_SOURCETYPE:
   case EN_SOURCEPAT:
     if (value < 0.0)
-      return (202);
+      return set_error(p->error_handle, 202);
     source = Node[index].S;
     if (source == NULL) {
       source = (struct Ssource *)malloc(sizeof(struct Ssource));
       if (source == NULL)
-        return (101);
+        return set_error(p->error_handle, 101);
       source->Type = CONCEN;
       source->C0 = 0.0;
       source->Pat = 0;
@@ -2551,21 +2784,21 @@ int DLLEXPORT EN_setnodevalue(EN_Project *p, int index, int code, EN_API_FLOAT_T
     } else if (code == EN_SOURCEPAT) {
       j = ROUND(value);
       if (j < 0 || j > Npats)
-        return (205);
+        return set_error(p->error_handle, 205);
       source->Pat = j;
     } else // code == EN_SOURCETYPE
     {
       j = ROUND(value);
       if (j < CONCEN || j > FLOWPACED)
-        return (251);
+        return set_error(p->error_handle, 251);
       else
         source->Type = (char)j;
     }
-    return (0);
+    return set_error(p->error_handle, 0);
 
   case EN_TANKLEVEL:
     if (index <= Njuncs)
-      return (251);
+      return set_error(p->error_handle, 251);
     j = index - Njuncs;
     if (Tank[j].A == 0.0) /* Tank is a reservoir */
     {
@@ -2577,7 +2810,7 @@ int DLLEXPORT EN_setnodevalue(EN_Project *p, int index, int code, EN_API_FLOAT_T
     } else {
       value = Node[index].El + value / Ucf[ELEV];
       if (value > Tank[j].Hmax || value < Tank[j].Hmin)
-        return (202);
+        return set_error(p->error_handle, 202);
       Tank[j].H0 = value;
       Tank[j].V0 = tankvolume(p, j, Tank[j].H0);
       // Resetting Volume in addition to initial volume
@@ -2592,9 +2825,9 @@ int DLLEXPORT EN_setnodevalue(EN_Project *p, int index, int code, EN_API_FLOAT_T
 
   case EN_TANKDIAM:
     if (value <= 0.0)
-      return (202);
+      return set_error(p->error_handle, 202);
     if (index <= Njuncs)
-      return (251);
+      return set_error(p->error_handle, 251);
     j = index - Njuncs;
     if (j > 0 && Tank[j].A > 0.0) {
       value /= Ucf[ELEV];
@@ -2603,81 +2836,81 @@ int DLLEXPORT EN_setnodevalue(EN_Project *p, int index, int code, EN_API_FLOAT_T
       Tank[j].V0 = tankvolume(p, j, Tank[j].H0);
       Tank[j].Vmax = tankvolume(p, j, Tank[j].Hmax);
     } else {
-      return (251);
+      return set_error(p->error_handle, 251);
     }
     break;
 
   case EN_MINVOLUME:
     if (value < 0.0)
-      return (202);
+      return set_error(p->error_handle, 202);
     if (index <= Njuncs)
-      return (251);
+      return set_error(p->error_handle, 251);
     j = index - Njuncs;
     if (j > 0 && Tank[j].A > 0.0) {
       Tank[j].Vmin = value / Ucf[VOLUME];
       Tank[j].V0 = tankvolume(p, j, Tank[j].H0);
       Tank[j].Vmax = tankvolume(p, j, Tank[j].Hmax);
     } else {
-      return (251);
+      return set_error(p->error_handle, 251);
     }
     break;
 
   case EN_MINLEVEL:
     if (value < 0.0)
-      return (202);
+      return set_error(p->error_handle, 202);
     if (index <= Njuncs)
-      return (251); // not a tank or reservoir
+      return set_error(p->error_handle, 251); // not a tank or reservoir
     j = index - Njuncs;
     if (Tank[j].A == 0.0)
-      return (251); // node is a reservoir
+      return set_error(p->error_handle, 251); // node is a reservoir
     Htmp = value / Ucf[ELEV] + Node[index].El;
     if (Htmp < Tank[j].Hmax && Htmp <= Tank[j].H0) {
       if (Tank[j].Vcurve > 0)
-        return (202);
+        return set_error(p->error_handle, 202);
       Tank[j].Hmin = Htmp;
       Tank[j].Vmin = tankvolume(p, j, Tank[j].Hmin);
     } else {
-      return (251);
+      return set_error(p->error_handle, 251);
     }
     break;
 
   case EN_MAXLEVEL:
     if (value < 0.0)
-      return (202);
+      return set_error(p->error_handle, 202);
     if (index <= Njuncs)
-      return (251); // not a tank or reservoir
+      return set_error(p->error_handle, 251); // not a tank or reservoir
     j = index - Njuncs;
     if (Tank[j].A == 0.0)
-      return (251); // node is a reservoir
+      return set_error(p->error_handle, 251); // node is a reservoir
     Htmp = value / Ucf[ELEV] + Node[index].El;
     if (Htmp > Tank[j].Hmin && Htmp >= Tank[j].H0) {
       if (Tank[j].Vcurve > 0)
-        return (202);
+        return set_error(p->error_handle, 202);
       Tank[j].Hmax = Htmp;
       Tank[j].Vmax = tankvolume(p, j, Tank[j].Hmax);
     } else {
-      return (251);
+      return set_error(p->error_handle, 251);
     }
     break;
 
   case EN_MIXMODEL:
     j = ROUND(value);
     if (index <= Njuncs)
-      return (251);
+      return set_error(p->error_handle, 251);
     if (j < MIX1 || j > LIFO)
-      return (202);
+      return set_error(p->error_handle, 202);
     if (index > Njuncs && Tank[index - Njuncs].A > 0.0) {
       Tank[index - Njuncs].MixModel = (char)j;
     } else {
-      return (251);
+      return set_error(p->error_handle, 251);
     }
     break;
 
   case EN_MIXFRACTION:
     if (value < 0.0 || value > 1.0)
-      return (202);
+      return set_error(p->error_handle, 202);
     if (index <= Njuncs)
-      return (251);
+      return set_error(p->error_handle, 251);
     j = index - Njuncs;
     if (j > 0 && Tank[j].A > 0.0) {
       Tank[j].V1max = value * Tank[j].Vmax;
@@ -2686,25 +2919,25 @@ int DLLEXPORT EN_setnodevalue(EN_Project *p, int index, int code, EN_API_FLOAT_T
 
   case EN_TANK_KBULK:
     if (index <= Njuncs)
-      return (251);
+      return set_error(p->error_handle, 251);
     j = index - Njuncs;
     if (j > 0 && Tank[j].A > 0.0) {
       Tank[j].Kb = value / SECperDAY;
       qu->Reactflag = 1;
     } else {
-      return (251);
+      return set_error(p->error_handle, 251);
     }
     break;
 
     /***  New parameter additions ends here. ***/ 
 
   default:
-    return (251);
+    return set_error(p->error_handle, 251);
   }
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_setlinkvalue(EN_Project *p, int index, int code,
+int DLLEXPORT EN_setlinkvalue(EN_ProjectHandle ph, int index, int code,
                               EN_API_FLOAT_TYPE v)
 
 /*----------------------------------------------------------------
@@ -2717,7 +2950,8 @@ int DLLEXPORT EN_setlinkvalue(EN_Project *p, int index, int code,
  **----------------------------------------------------------------
  */
 {
-  
+  EN_Project *p = (EN_Project*)ph;
+
   EN_Network *net = &p->network;
   hydraulics_t *hyd = &p->hydraulics;
   quality_t *qu = &p->quality;
@@ -2733,14 +2967,14 @@ int DLLEXPORT EN_setlinkvalue(EN_Project *p, int index, int code,
   double r, value = v;
 
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index <= 0 || index > Nlinks)
-    return (204);
+    return set_error(p->error_handle, 204);
   switch (code) {
   case EN_DIAMETER:
     if (Link[index].Type != EN_PUMP) {
       if (value <= 0.0)
-        return (202);
+        return set_error(p->error_handle, 202);
       value /= Ucf[DIAM];                /* Convert to feet */
       r = Link[index].Diam / value;      /* Ratio of old to new diam */
       Link[index].Km *= SQR(r) * SQR(r); /* Adjust minor loss factor */
@@ -2752,7 +2986,7 @@ int DLLEXPORT EN_setlinkvalue(EN_Project *p, int index, int code,
   case EN_LENGTH:
     if (Link[index].Type <= EN_PIPE) {
       if (value <= 0.0)
-        return (202);
+        return set_error(p->error_handle, 202);
       Link[index].Len = value / Ucf[ELEV];
       resistcoeff(p, index);
     }
@@ -2761,7 +2995,7 @@ int DLLEXPORT EN_setlinkvalue(EN_Project *p, int index, int code,
   case EN_ROUGHNESS:
     if (Link[index].Type <= EN_PIPE) {
       if (value <= 0.0)
-        return (202);
+        return set_error(p->error_handle, 202);
       Link[index].Kc = value;
       if (hyd->Formflag == DW)
         Link[index].Kc /= (1000.0 * Ucf[ELEV]);
@@ -2772,7 +3006,7 @@ int DLLEXPORT EN_setlinkvalue(EN_Project *p, int index, int code,
   case EN_MINORLOSS:
     if (Link[index].Type != EN_PUMP) {
       if (value <= 0.0)
-        return (202);
+        return set_error(p->error_handle, 202);
       Link[index].Km =
           0.02517 * value / SQR(Link[index].Diam) / SQR(Link[index].Diam);
     }
@@ -2782,10 +3016,10 @@ int DLLEXPORT EN_setlinkvalue(EN_Project *p, int index, int code,
   case EN_STATUS:
     /* Cannot set status for a check valve */
     if (Link[index].Type == EN_CVPIPE)
-      return (207);
+      return set_error(p->error_handle, 207);
     s = (char)ROUND(value);
     if (s < 0 || s > 1)
-      return (251);
+      return set_error(p->error_handle, 251);
     if (code == EN_INITSTATUS)
       setlinkstatus(p, index, s, &Link[index].Stat, &Link[index].Kc);
     else
@@ -2795,9 +3029,9 @@ int DLLEXPORT EN_setlinkvalue(EN_Project *p, int index, int code,
   case EN_INITSETTING:
   case EN_SETTING:
     if (value < 0.0)
-      return (202);
+      return set_error(p->error_handle, 202);
     if (Link[index].Type == EN_PIPE || Link[index].Type == EN_CVPIPE)
-      return (ENsetlinkvalue(index, EN_ROUGHNESS, v));
+      return set_error(p->error_handle, ENsetlinkvalue(index, EN_ROUGHNESS, v));
     else {
       switch (Link[index].Type) {
       case EN_PUMP:
@@ -2815,10 +3049,10 @@ int DLLEXPORT EN_setlinkvalue(EN_Project *p, int index, int code,
 
       /***  Updated 9/7/00  ***/
       case EN_GPV:
-        return (202); /* Cannot modify setting for GPV */
+        return set_error(p->error_handle, 202); /* Cannot modify setting for GPV */
 
       default:
-        return (251);
+        return set_error(p->error_handle, 251);
       }
       if (code == EN_INITSETTING)
         setlinksetting(p, index, value, &Link[index].Stat, &Link[index].Kc);
@@ -2843,15 +3077,17 @@ int DLLEXPORT EN_setlinkvalue(EN_Project *p, int index, int code,
     break;
 
   default:
-    return (251);
+    return set_error(p->error_handle, 251);
   }
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_addpattern(EN_Project *p, char *id) {
+int DLLEXPORT EN_addpattern(EN_ProjectHandle ph, char *id) {
   int i, j, n, err = 0;
   Spattern *tmpPat;
 
+  EN_Project *p = (EN_Project*)ph;
+
   EN_Network *net = &p->network;
   parser_data_t *par = &p->parser;
   
@@ -2863,21 +3099,21 @@ int DLLEXPORT EN_addpattern(EN_Project *p, char *id) {
   /* Check if a pattern with same id already exists */
 
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (ENgetpatternindex(id, &i) == 0)
-    return (215);
+    return set_error(p->error_handle, 215);
 
   /* Check that id name is not too long */
 
   if (strlen(id) > MAXID)
-    return (250);
+    return set_error(p->error_handle, 250);
 
   /* Allocate memory for a new array of patterns */
 
   n = Npats + 1;
   tmpPat = (Spattern *)calloc(n + 1, sizeof(Spattern));
   if (tmpPat == NULL)
-    return (101);
+    return set_error(p->error_handle, 101);
 
   /* Copy contents of old pattern array to new one */
 
@@ -2909,7 +3145,7 @@ int DLLEXPORT EN_addpattern(EN_Project *p, char *id) {
       if (tmpPat[i].F)
         free(tmpPat[i].F);
     free(tmpPat);
-    return (101);
+    return set_error(p->error_handle, 101);
   }
 
   // Replace old pattern array with new one
@@ -2920,12 +3156,14 @@ int DLLEXPORT EN_addpattern(EN_Project *p, char *id) {
   Pattern = tmpPat;
   net->Npats = n;
   par->MaxPats = n;
-  return 0;
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_setpattern(EN_Project *p, int index, EN_API_FLOAT_TYPE *f, int n) {
+int DLLEXPORT EN_setpattern(EN_ProjectHandle ph, int index, EN_API_FLOAT_TYPE *f, int n) {
   int j;
 
+  EN_Project *p = (EN_Project*)ph;
+
   EN_Network *net = &p->network;
   Spattern *Pattern = net->Pattern;
   const int Npats = net->Npats;
@@ -2933,26 +3171,28 @@ int DLLEXPORT EN_setpattern(EN_Project *p, int index, EN_API_FLOAT_TYPE *f, int
   
   /* Check for valid arguments */
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index <= 0 || index > Npats)
-    return (205);
+    return set_error(p->error_handle, 205);
   if (n <= 0)
-    return (202);
+    return set_error(p->error_handle, 202);
 
   /* Re-set number of time periods & reallocate memory for multipliers */
   Pattern[index].Length = n;
   Pattern[index].F = (double *)realloc(Pattern[index].F, n * sizeof(double));
   if (Pattern[index].F == NULL)
-    return (101);
+    return set_error(p->error_handle, 101);
 
   /* Load multipliers into pattern */
   for (j = 0; j < n; j++)
     Pattern[index].F[j] = f[j];
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_setpatternvalue(EN_Project *p, int index, int period, EN_API_FLOAT_TYPE value) {
+int DLLEXPORT EN_setpatternvalue(EN_ProjectHandle ph, int index, int period, EN_API_FLOAT_TYPE value) {
   
+  EN_Project *p = (EN_Project*)ph;
+
   EN_Network *net = &p->network;
   
   Spattern *Pattern = net->Pattern;
@@ -2961,17 +3201,19 @@ int DLLEXPORT EN_setpatternvalue(EN_Project *p, int index, int period, EN_API_FL
   
   
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index <= 0 || index > Npats)
-    return (205);
+    return set_error(p->error_handle, 205);
   if (period <= 0 || period > Pattern[index].Length)
-    return (251);
+    return set_error(p->error_handle, 251);
   Pattern[index].F[period - 1] = value;
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_addcurve(EN_Project *p, char *id) {
+int DLLEXPORT EN_addcurve(EN_ProjectHandle ph, char *id) {
   
+  EN_Project *p = (EN_Project*)ph;
+
   EN_Network *net = &p->network;
   parser_data_t *par = &p->parser;
   Scurve *Curve = net->Curve;
@@ -2982,21 +3224,21 @@ int DLLEXPORT EN_addcurve(EN_Project *p, char *id) {
   /* Check if a curve with same id already exists */
 
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (ENgetcurveindex(id, &i) == 0)
-    return (215);
+    return set_error(p->error_handle, 215);
 
   /* Check that id name is not too long */
 
   if (strlen(id) > MAXID)
-    return (250);
+    return set_error(p->error_handle, 250);
 
   /* Allocate memory for a new array of curves */
 
   n = net->Ncurves + 1;
   tmpCur = (Scurve *)calloc(n + 1, sizeof(Scurve));
   if (tmpCur == NULL)
-    return (101);
+    return set_error(p->error_handle, 101);
 
   /* Copy contents of old curve array to new one */
 
@@ -3042,7 +3284,7 @@ int DLLEXPORT EN_addcurve(EN_Project *p, char *id) {
         free(tmpCur[i].Y);
     }
     free(tmpCur);
-    return (101);
+    return set_error(p->error_handle, 101);
   }
 
   // Replace old curves array with new one
@@ -3055,65 +3297,71 @@ int DLLEXPORT EN_addcurve(EN_Project *p, char *id) {
   net->Curve = tmpCur;
   net->Ncurves = n;
   par->MaxCurves = n;
-  return 0;
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_setcurve(EN_Project *p, int index, EN_API_FLOAT_TYPE *x, EN_API_FLOAT_TYPE *y, int n) {
+int DLLEXPORT EN_setcurve(EN_ProjectHandle ph, int index, EN_API_FLOAT_TYPE *x, EN_API_FLOAT_TYPE *y, int n) {
   
+  EN_Project *p = (EN_Project*)ph;
+
   EN_Network *net = &p->network;  
   Scurve *Curve = net->Curve;  
   int j;
 
   /* Check for valid arguments */
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index <= 0 || index > net->Ncurves)
-    return (206);
+    return set_error(p->error_handle, 206);
   if (n <= 0)
-    return (202);
+    return set_error(p->error_handle, 202);
 
   /* Re-set number of points & reallocate memory for values */
   Curve[index].Npts = n;
   Curve[index].X = (double *)realloc(Curve[index].X, n * sizeof(double));
   Curve[index].Y = (double *)realloc(Curve[index].Y, n * sizeof(double));
   if (Curve[index].X == NULL)
-    return (101);
+    return set_error(p->error_handle, 101);
   if (Curve[index].Y == NULL)
-    return (101);
+    return set_error(p->error_handle, 101);
 
   /* Load values into curve */
   for (j = 0; j < n; j++) {
     Curve[index].X[j] = x[j];
     Curve[index].Y[j] = y[j];
   }
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_setcurvevalue(EN_Project *p, int index, int pnt, EN_API_FLOAT_TYPE x, EN_API_FLOAT_TYPE y) {
-  
+int DLLEXPORT EN_setcurvevalue(EN_ProjectHandle ph, int index, int pnt, EN_API_FLOAT_TYPE x, EN_API_FLOAT_TYPE y) {
+
+  EN_Project *p = (EN_Project*)ph;
+
   EN_Network *net = &p->network;
   Scurve *Curve = net->Curve;
   const int Ncurves = net->Ncurves;
   
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index <= 0 || index > Ncurves)
-    return (206);
+    return set_error(p->error_handle, 206);
   if (pnt <= 0 || pnt > Curve[index].Npts)
-    return (251);
+    return set_error(p->error_handle, 251);
   Curve[index].X[pnt - 1] = x;
   Curve[index].Y[pnt - 1] = y;
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_settimeparam(EN_Project *p, int code, long value)
+int DLLEXPORT EN_settimeparam(EN_ProjectHandle ph, int code, long value)
 {
+  EN_Project *p = (EN_Project*)ph;
+
   report_options_t *rep = &p->report;
   quality_t *qu = &p->quality;
   time_options_t *time = &p->time_options;
   
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (p->hydraulics.OpenHflag || p->quality.OpenQflag) {
     // --> there's nothing wrong with changing certain time parameters during a
     // simulation run, or before the run has started.
@@ -3129,7 +3377,7 @@ int DLLEXPORT EN_settimeparam(EN_Project *p, int code, long value)
      */
   }
   if (value < 0)
-    return (202);
+    return set_error(p->error_handle, 202);
   switch (code) {
   case EN_DURATION:
     time->Dur = value;
@@ -3139,7 +3387,7 @@ int DLLEXPORT EN_settimeparam(EN_Project *p, int code, long value)
 
   case EN_HYDSTEP:
     if (value == 0)
-      return (202);
+      return set_error(p->error_handle, 202);
     time->Hstep = value;
     time->Hstep = MIN(time->Pstep, time->Hstep);
     time->Hstep = MIN(time->Rstep, time->Hstep);
@@ -3148,14 +3396,14 @@ int DLLEXPORT EN_settimeparam(EN_Project *p, int code, long value)
 
   case EN_QUALSTEP:
     if (value == 0)
-      return (202);
+      return set_error(p->error_handle, 202);
     qu->Qstep = value;
     qu->Qstep = MIN(qu->Qstep, time->Hstep);
     break;
 
   case EN_PATTERNSTEP:
     if (value == 0)
-      return (202);
+      return set_error(p->error_handle, 202);
     time->Pstep = value;
     if (time->Hstep > time->Pstep)
       time->Hstep = time->Pstep;
@@ -3167,7 +3415,7 @@ int DLLEXPORT EN_settimeparam(EN_Project *p, int code, long value)
 
   case EN_REPORTSTEP:
     if (value == 0)
-      return (202);
+      return set_error(p->error_handle, 202);
     time->Rstep = value;
     if (time->Hstep > time->Rstep)
       time->Hstep = time->Rstep;
@@ -3175,20 +3423,20 @@ int DLLEXPORT EN_settimeparam(EN_Project *p, int code, long value)
 
   case EN_REPORTSTART:
     if (time->Rstart > time->Dur)
-      return (202);
+      return set_error(p->error_handle, 202);
     time->Rstart = value;
     break;
 
   case EN_RULESTEP:
     if (value == 0)
-      return (202);
+      return set_error(p->error_handle, 202);
     time->Rulestep = value;
     time->Rulestep = MIN(time->Rulestep, time->Hstep);
     break;
 
   case EN_STATISTIC:
     if (value > RANGE)
-      return (202);
+      return set_error(p->error_handle, 202);
     rep->Tstatflag = (char)value;
     break;
 
@@ -3201,12 +3449,12 @@ int DLLEXPORT EN_settimeparam(EN_Project *p, int code, long value)
     break;
 
   default:
-    return (251);
+    return set_error(p->error_handle, 251);
   }
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_setoption(EN_Project *p, int code, EN_API_FLOAT_TYPE v)
+int DLLEXPORT EN_setoption(EN_ProjectHandle ph, int code, EN_API_FLOAT_TYPE v)
 /*----------------------------------------------------------------
  **  Input:   code  = option code (see EPANET2.H)
  **           v = option value
@@ -3216,6 +3464,8 @@ int DLLEXPORT EN_setoption(EN_Project *p, int code, EN_API_FLOAT_TYPE v)
  **----------------------------------------------------------------
  */
 {
+  EN_Project *p = (EN_Project*)ph;
+
   EN_Network *net = &p->network;
   hydraulics_t *hyd = &p->hydraulics;
   quality_t *qu = &p->quality;
@@ -3228,26 +3478,26 @@ int DLLEXPORT EN_setoption(EN_Project *p, int code, EN_API_FLOAT_TYPE v)
   int i, j;
   double Ke, n, ucf, value = v;
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   switch (code) {
   case EN_TRIALS:
     if (value < 1.0)
-      return (202);
+      return set_error(p->error_handle, 202);
     hyd->MaxIter = (int)value;
     break;
   case EN_ACCURACY:
     if (value < 1.e-5 || value > 1.e-1)
-      return (202);
+      return set_error(p->error_handle, 202);
     hyd->Hacc = value;
     break;
   case EN_TOLERANCE:
     if (value < 0.0)
-      return (202);
+      return set_error(p->error_handle, 202);
     qu->Ctol = value / Ucf[QUALITY];
     break;
   case EN_EMITEXPON:
     if (value <= 0.0)
-      return (202);
+      return set_error(p->error_handle, 202);
     n = 1.0 / value;
     ucf = pow(Ucf[FLOW], n) / Ucf[PRESSURE];
     for (i = 1; i <= Njuncs; i++) {
@@ -3260,38 +3510,43 @@ int DLLEXPORT EN_setoption(EN_Project *p, int code, EN_API_FLOAT_TYPE v)
     break;
   case EN_DEMANDMULT:
     if (value <= 0.0)
-      return (202);
+      return set_error(p->error_handle, 202);
     hyd->Dmult = value;
     break;
 
   case EN_HEADERROR:
     if (value < 0.0)
-        return (202);
+        return set_error(p->error_handle, 202);
     hyd->HeadErrorLimit = value / Ucf[HEAD];
     break;
   case EN_FLOWCHANGE:
       if (value < 0.0)
-          return (202);
+          return set_error(p->error_handle, 202);
       hyd->FlowChangeLimit = value / Ucf[FLOW];
       break;
 
   default:
-    return (251);
+    return set_error(p->error_handle, 251);
   }
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_setstatusreport(EN_Project *p, int code) {
+int DLLEXPORT EN_setstatusreport(EN_ProjectHandle ph, int code) {
   int errcode = 0;
+
+  EN_Project *p = (EN_Project*)ph;
+
   if (code >= 0 && code <= 2)
     p->report.Statflag = (char)code;
   else
     errcode = 202;
-  return (errcode);
+  return set_error(p->error_handle, errcode);
 }
 
-int DLLEXPORT EN_setqualtype(EN_Project *p, int qualcode, char *chemname, char *chemunits, char *tracenode) {
+int DLLEXPORT EN_setqualtype(EN_ProjectHandle ph, int qualcode, char *chemname, char *chemunits, char *tracenode) {
   
+  EN_Project *p = (EN_Project*)ph;
+
   EN_Network *net = &p->network;
   report_options_t *rep = &p->report;
   quality_t *qu = &p->quality;
@@ -3303,9 +3558,9 @@ int DLLEXPORT EN_setqualtype(EN_Project *p, int qualcode, char *chemname, char *
   double ccf = 1.0;
 
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (qualcode < EN_NONE || qualcode > EN_TRACE)
-    return (251);
+    return set_error(p->error_handle, 251);
   qu->Qualflag = (char)qualcode;
   qu->Ctol *= Ucf[QUALITY];
   if (qu->Qualflag == CHEM) /* Chemical constituent */
@@ -3323,7 +3578,7 @@ int DLLEXPORT EN_setqualtype(EN_Project *p, int qualcode, char *chemname, char *
   {
     qu->TraceNode = findnode(net,tracenode);
     if (qu->TraceNode == 0)
-      return (203);
+      return set_error(p->error_handle, 203);
     strncpy(qu->ChemName, u_PERCENT, MAXID);
     strncpy(qu->ChemUnits, tracenode, MAXID);
 
@@ -3352,26 +3607,30 @@ int DLLEXPORT EN_setqualtype(EN_Project *p, int qualcode, char *chemname, char *
   Ucf[REACTRATE] = ccf;
   qu->Ctol /= Ucf[QUALITY];
 
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_getheadcurveindex(EN_Project *p, int index, int *curveindex) {
+int DLLEXPORT EN_getheadcurveindex(EN_ProjectHandle ph, int index, int *curveindex) {
   
+  EN_Project *p = (EN_Project*)ph;
+
   EN_Network *net = &p->network;  
   Slink *Link = net->Link;
   Spump *Pump = net->Pump;
   const int Nlinks = net->Nlinks;
   
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index < 1 || index > Nlinks || EN_PUMP != Link[index].Type)
-    return (204);
+    return set_error(p->error_handle, 204);
   *curveindex = Pump[findpump(net, index)].Hcurve;
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_setheadcurveindex(EN_Project *p, int index, int curveindex) {
+int DLLEXPORT EN_setheadcurveindex(EN_ProjectHandle ph, int index, int curveindex) {
   
+  EN_Project *p = (EN_Project*)ph;
+
   EN_Network *net = &p->network;
   
   Slink *Link = net->Link;
@@ -3383,12 +3642,12 @@ int DLLEXPORT EN_setheadcurveindex(EN_Project *p, int index, int curveindex) {
   Spump *pump;
   
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index < 1 || index > Nlinks || EN_PUMP != Link[index].Type) {
-    return (204);
+    return set_error(p->error_handle, 204);
   }
   if (curveindex <= 0 || curveindex > Ncurves) {
-    return (206);
+    return set_error(p->error_handle, 206);
   }
   pIdx = findpump(net, index);
   pump = &p->network.Pump[pIdx];
@@ -3407,11 +3666,13 @@ int DLLEXPORT EN_setheadcurveindex(EN_Project *p, int index, int curveindex) {
   pump->Hmax /= Ucf[HEAD];
   
   p->network.Curve[curveindex].Type = P_CURVE;
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_getpumptype(EN_Project *p, int index, int *type) {
+int DLLEXPORT EN_getpumptype(EN_ProjectHandle ph, int index, int *type) {
   
+  EN_Project *p = (EN_Project*)ph;
+
   EN_Network *net = &p->network;
   
   Slink *Link = net->Link;
@@ -3420,23 +3681,25 @@ int DLLEXPORT EN_getpumptype(EN_Project *p, int index, int *type) {
   
   *type = -1;
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index < 1 || index > Nlinks || EN_PUMP != Link[index].Type)
-    return (204);
+    return set_error(p->error_handle, 204);
   *type = Pump[findpump(&p->network, index)].Ptype;
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_getcurvetype(EN_Project *p, int curveindex, int *type) {
+int DLLEXPORT EN_getcurvetype(EN_ProjectHandle ph, int curveindex, int *type) {
   
+  EN_Project *p = (EN_Project*)ph;
+
   EN_Network *net = &p->network;
     
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (curveindex < 1 || curveindex > net->Ncurves)
-    return (206);
+    return set_error(p->error_handle, 206);
   *type = net->Curve[curveindex].Type;
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
 /*
@@ -3445,7 +3708,7 @@ int DLLEXPORT EN_getcurvetype(EN_Project *p, int curveindex, int *type) {
 ----------------------------------------------------------------
 */
 
-int openfiles(EN_Project *p, char *f1, char *f2, char *f3)
+int openfiles(EN_Project *p, const char *f1, const char *f2, const char *f3)
 /*----------------------------------------------------------------
 **  Input:   f1 = pointer to name of input file
 **           f2 = pointer to name of report file
@@ -3480,23 +3743,23 @@ int openfiles(EN_Project *p, char *f1, char *f2, char *f3)
   if (strcomp(f1, f2) || strcomp(f1, f3) ||
       (strcomp(f2, f3) && (strlen(f2) > 0 || strlen(f3) > 0))) {
     writecon(FMT04);
-    return (301);
+    return set_error(p->error_handle, 301);
   }
 
   /* Attempt to open input and report files */
   if ((par->InFile = fopen(f1, "rt")) == NULL) {
     writecon(FMT05);
     writecon(f1);
-    return (302);
+    return set_error(p->error_handle, 302);
   }
   if (strlen(f2) == 0)
     rep->RptFile = stdout;
   else if ((rep->RptFile = fopen(f2, "wt")) == NULL) {
     writecon(FMT06);
-    return (303);
+    return set_error(p->error_handle, 303);
   }
 
-  return (0);
+  return set_error(p->error_handle, 0);
 } /* End of openfiles */
 
 int openhydfile(EN_Project *p)
@@ -3527,7 +3790,7 @@ int openhydfile(EN_Project *p)
   /* If HydFile currently open, then close it if its not a scratch file */
   if (out->HydFile != NULL) {
     if (out->Hydflag == SCRATCH)
-      return (0);
+      return set_error(p->error_handle, 0);
     fclose(out->HydFile);
   }
 
@@ -3547,7 +3810,7 @@ int openhydfile(EN_Project *p)
     break;
   }
   if (out->HydFile == NULL)
-    return (305);
+    return set_error(p->error_handle, 305);
 
   /* If a previous hydraulics solution is not being used, then */
   /* save the current network size parameters to the file.     */
@@ -3571,22 +3834,22 @@ int openhydfile(EN_Project *p)
   if (out->Hydflag == USE) {
     fread(&magic, sizeof(INT4), 1, out->HydFile);
     if (magic != MAGICNUMBER)
-      return (306);
+      return set_error(p->error_handle, 306);
     fread(&version, sizeof(INT4), 1, out->HydFile);
     if (version != ENGINE_VERSION)
-      return (306);
+      return set_error(p->error_handle, 306);
     if (fread(nsize, sizeof(INT4), 6, out->HydFile) < 6)
-      return (306);
+      return set_error(p->error_handle, 306);
     if (nsize[0] != Nnodes || nsize[1] != Nlinks || nsize[2] != Ntanks ||
         nsize[3] != Npumps || nsize[4] != Nvalves || nsize[5] != time->Dur)
-      return (306);
+      return set_error(p->error_handle, 306);
     p->save_options.SaveHflag = TRUE;
   }
 
   /* Save current position in hydraulics file  */
   /* where storage of hydraulic results begins */
   out->HydOffset = ftell(out->HydFile);
-  return (errcode);
+  return set_error(p->error_handle, errcode);
 }
 
 int openoutfile(EN_Project *p)
@@ -3654,7 +3917,7 @@ int openoutfile(EN_Project *p)
     } else
       out->TmpOutFile = out->OutFile;
   }
-  return (errcode);
+  return set_error(p->error_handle, errcode);
 }
 
 /*
@@ -3828,7 +4091,7 @@ int allocdata(EN_Project *p)
   /* Allocate memory for rule base (see RULES.C) */
   if (!errcode)
     errcode = allocrules(p);
-  return (errcode);
+  return set_error(p->error_handle, errcode);
 } /* End of allocdata */
 
 void freeTmplist(STmplist *t)
@@ -3978,35 +4241,6 @@ char *getTmpName(EN_Project *p, char *fname)
     // --- free the pointer returned by _tempnam
     if (name) free(name);
 
-/*
-///////////////////  DEPRECATED   /////////////////////////////////////
-// --- for Windows systems:
-#ifdef WINDOWS
-  // --- use system function tmpnam() to create a temporary file name
-  char name[MAXFNAME + 1];
-  int n;
-  
-  tmpnam(name);
-  
-  // --- if user supplied the name of a temporary directory,
-  //     then make it be the prefix of the full file name
-  n = (int)strlen(out->TmpDir);
-  if (n > 0) {
-    strcpy(fname, out->TmpDir);
-    if (fname[n - 1] != '\\')
-      strcat(fname, "\\");
-  }
-
-  // --- otherwise, use the relative path notation as the file name
-  //     prefix so that the file will be placed in the current directory
-  else {
-    strcpy(fname, ".\\");
-  }
-
-  // --- now add the prefix to the file name
-  strcat(fname, name);
-*/
-
 // --- for non-Windows systems:
 #else
   // --- use system function mkstemp() to create a temporary file name
@@ -4016,7 +4250,7 @@ char *getTmpName(EN_Project *p, char *fname)
   return fname;
 }
 
-int strcomp(char *s1, char *s2)
+int strcomp(const char *s1, const char *s2)
 /*---------------------------------------------------------------
 **  Input:   s1 = character string
 **           s2 = character string
@@ -4156,11 +4390,11 @@ char *geterrmsg(int errcode, char *msg)
 */
 {
   switch (errcode) { /* Warnings */
-#define DAT(code,enumer,string) case code: strcpy(msg, string); break;
+#define DAT(code,enumer,string) case code: msg = string; break;
 #include "errors.dat"
 #undef DAT
     default:
-      strcpy(msg, "");
+      msg = "";
   }
   return (msg);
 }
@@ -4182,7 +4416,7 @@ void errmsg(EN_Project *p, int errcode)
   }
 }
 
-void writecon(char *s)
+void writecon(const char *s)
 /*----------------------------------------------------------------
 **  Input:   text string
 **  Output:  none
@@ -4211,44 +4445,52 @@ void writewin(void (*vp)(char *), char *s)
   }
 }
 
-int DLLEXPORT EN_getnumdemands(EN_Project *p, int nodeIndex, int *numDemands) {
+int DLLEXPORT EN_getnumdemands(EN_ProjectHandle ph, int nodeIndex, int *numDemands) {
   Pdemand d;
   int n = 0;
+
+  EN_Project *p = (EN_Project*)ph;
+
   /* Check for valid arguments */
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (nodeIndex <= 0 || nodeIndex > p->network.Nnodes)
-    return (203);
+    return set_error(p->error_handle, 203);
   for (d = p->network.Node[nodeIndex].D; d != NULL; d = d->next)
     n++;
   *numDemands = n;
-  return 0;
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_getbasedemand(EN_Project *p, int nodeIndex, int demandIdx, EN_API_FLOAT_TYPE *baseDemand) {
+int DLLEXPORT EN_getbasedemand(EN_ProjectHandle ph, int nodeIndex, int demandIdx, EN_API_FLOAT_TYPE *baseDemand) {
   Pdemand d;
   int n = 1;
+
+  EN_Project *p = (EN_Project*)ph;
+
   /* Check for valid arguments */
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (nodeIndex <= 0 || nodeIndex > p->network.Nnodes)
-    return (203);
+    return set_error(p->error_handle, 203);
   if (nodeIndex <= p->network.Njuncs) {
     for (d = p->network.Node[nodeIndex].D; n < demandIdx && d != NULL; d = d->next) {
       n++;
     }
     if (n != demandIdx) {
-      return (253);
+      return set_error(p->error_handle, 253);
     }
     *baseDemand = (EN_API_FLOAT_TYPE)(d->Base * p->Ucf[FLOW]);
   } else {
     *baseDemand = (EN_API_FLOAT_TYPE)(0.0);
   }
-  return 0;
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_setbasedemand(EN_Project *pr, int nodeIndex, int demandIdx, EN_API_FLOAT_TYPE baseDemand) {
+int DLLEXPORT EN_setbasedemand(EN_ProjectHandle ph, int nodeIndex, int demandIdx, EN_API_FLOAT_TYPE baseDemand) {
   
+  EN_Project *pr = (EN_Project*)ph;
+
   EN_Network *net = &pr->network;
   Snode *Node = net->Node;
   
@@ -4261,21 +4503,23 @@ int DLLEXPORT EN_setbasedemand(EN_Project *pr, int nodeIndex, int demandIdx, EN_
   int n = 1;
   /* Check for valid arguments */
   if (!pr->Openflag)
-    return (102);
+    return set_error(pr->error_handle, 102);
   if (nodeIndex <= 0 || nodeIndex > Nnodes)
-    return (203);
+    return set_error(pr->error_handle, 203);
   if (nodeIndex <= Njuncs) {
     for (d = Node[nodeIndex].D; n < demandIdx && d != NULL; d = d->next)
       n++;
     if (n != demandIdx)
-      return (253);
+      return set_error(pr->error_handle, 253);
     d->Base = baseDemand / Ucf[FLOW];
   }
-  return 0;
+  return set_error(pr->error_handle, 0);
 }
 
-int DLLEXPORT EN_getdemandpattern(EN_Project *p, int nodeIndex, int demandIdx, int *pattIdx) {
+int DLLEXPORT EN_getdemandpattern(EN_ProjectHandle ph, int nodeIndex, int demandIdx, int *pattIdx) {
   
+  EN_Project *p = (EN_Project*)ph;
+
   EN_Network *net = &p->network;
   Snode *Node = net->Node;
   const int Nnodes = net->Nnodes;
@@ -4284,19 +4528,21 @@ int DLLEXPORT EN_getdemandpattern(EN_Project *p, int nodeIndex, int demandIdx, i
   int n = 1;
   /* Check for valid arguments */
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (nodeIndex <= 0 || nodeIndex > Nnodes)
-    return (203);
+    return set_error(p->error_handle, 203);
   for (d = Node[nodeIndex].D; n < demandIdx && d != NULL; d = d->next)
     n++;
   if (n != demandIdx)
-    return (253);
+    return set_error(p->error_handle, 253);
   *pattIdx = d->Pat;
-  return 0;
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_getaveragepatternvalue(EN_Project *p, int index, EN_API_FLOAT_TYPE *value) {
+int DLLEXPORT EN_getaveragepatternvalue(EN_ProjectHandle ph, int index, EN_API_FLOAT_TYPE *value) {
   
+  EN_Project *p = (EN_Project*)ph;
+
   EN_Network *net = &p->network;
   
   Spattern *Pattern = net->Pattern;
@@ -4305,34 +4551,36 @@ int DLLEXPORT EN_getaveragepatternvalue(EN_Project *p, int index, EN_API_FLOAT_T
   int i;
   *value = 0.0;
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index < 1 || index > Npats)
-    return (205);
+    return set_error(p->error_handle, 205);
   // if (period < 1 || period > Pattern[index].Length) return(251);
   for (i = 0; i < Pattern[index].Length; i++) {
     *value += (EN_API_FLOAT_TYPE)Pattern[index].F[i];
   }
   *value /= (EN_API_FLOAT_TYPE)Pattern[index].Length;
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_setlinktype(EN_Project *p, char *id, EN_LinkType toType) {
+int DLLEXPORT EN_setlinktype(EN_ProjectHandle ph, char *id, EN_LinkType toType) {
   int i;
   EN_LinkType fromType;
   
+  EN_Project *p = (EN_Project*)ph;
+
   EN_Network *net = &p->network;
 
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
 
   /* Check if a link with the id exists */
   if (EN_getlinkindex(p, id, &i) != 0)
-    return (215);
+    return set_error(p->error_handle, 215);
 
   /* Get the current type of the link */
   ENgetlinktype(i, &fromType);
   if (fromType == toType)
-    return (0);
+    return set_error(p->error_handle, 0);
 
   /* Change link from Pipe */
   if (toType <= EN_PIPE) {
@@ -4350,13 +4598,16 @@ int DLLEXPORT EN_setlinktype(EN_Project *p, char *id, EN_LinkType toType) {
   } else if (fromType == EN_PUMP) {
     net->Npumps--;
   }
-  return 0;
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_addnode(EN_Project *p, char *id, EN_NodeType nodeType) {
+int DLLEXPORT EN_addnode(EN_ProjectHandle ph, char *id, EN_NodeType nodeType) {
   int i, nIdx;
   int index;
   struct Sdemand *demand;
+
+  EN_Project *p = (EN_Project*)ph;
+
   EN_Network *net = &p->network;
   hydraulics_t *hyd = &p->hydraulics;
   quality_t *qu = &p->quality;
@@ -4366,13 +4617,13 @@ int DLLEXPORT EN_addnode(EN_Project *p, char *id, EN_NodeType nodeType) {
   
   /* Check if a node with same id already exists */
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (ENgetnodeindex(id, &i) == 0)
-    return (215);
+    return set_error(p->error_handle, 215);
 
   /* Check that id name is not too long */
   if (strlen(id) > MAXID)
-    return (250);
+    return set_error(p->error_handle, 250);
 
   /* Grow arrays to accomodate the new values */
   net->Node = (Snode *)realloc(net->Node, (net->Nnodes + 2) * sizeof(Snode));
@@ -4464,13 +4715,16 @@ int DLLEXPORT EN_addnode(EN_Project *p, char *id, EN_NodeType nodeType) {
 
   /* Insert new node into hash table */
   ENHashTableInsert(net->NodeHashTable, node->ID, nIdx); /* see HASH.C */
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_addlink(EN_Project *p, char *id, EN_LinkType linkType, char *fromNode,
+int DLLEXPORT EN_addlink(EN_ProjectHandle ph, char *id, EN_LinkType linkType, char *fromNode,
                         char *toNode) {
   int i, n;
   int N1, N2;
+
+  EN_Project *p = (EN_Project*)ph;
+
   EN_Network *net = &p->network;
   hydraulics_t *hyd = &p->hydraulics;
   Slink *link;
@@ -4478,21 +4732,21 @@ int DLLEXPORT EN_addlink(EN_Project *p, char *id, EN_LinkType linkType, char *fr
 
   /* Check if a link with same id already exists */
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (ENgetlinkindex(id, &i) == 0)
-    return (215);
+    return set_error(p->error_handle, 215);
 
   /* Lookup the from and to nodes */
   N1 = ENHashTableFind(net->NodeHashTable, fromNode);
   N2 = ENHashTableFind(net->NodeHashTable, toNode);
 
   if (N1 == 0 || N2 == 0) {
-    return (203);
+    return set_error(p->error_handle, 203);
   }
 
   /* Check that id name is not too long */
   if (strlen(id) > MAXID)
-    return (250);
+    return set_error(p->error_handle, 250);
 
   net->Nlinks++;
   n = net->Nlinks;
@@ -4574,19 +4828,22 @@ int DLLEXPORT EN_addlink(EN_Project *p, char *id, EN_LinkType linkType, char *fr
   }
   
   ENHashTableInsert(net->LinkHashTable, link->ID, n);
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_deletelink(EN_Project *p, int index) {
+int DLLEXPORT EN_deletelink(EN_ProjectHandle ph, int index) {
   int i;
   EN_LinkType linkType;
+
+  EN_Project *p = (EN_Project*)ph;
+
   EN_Network *net = &p->network;
   Slink *link;
   
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index <= 0 || index > net->Nlinks)
-    return (203);
+    return set_error(p->error_handle, 203);
 
   EN_getlinktype(p, index, &linkType);
 
@@ -4633,19 +4890,21 @@ int DLLEXPORT EN_deletelink(EN_Project *p, int index) {
     net->Nvalves--;
   }
 
-  return 0;
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_deletenode(EN_Project *p, int index) {
+int DLLEXPORT EN_deletenode(EN_ProjectHandle ph, int index) {
+
+  EN_Project *p = (EN_Project*)ph;
 
   EN_Network *net = &p->network;
   
   int i, nodeType;
 
   if (!p->Openflag)
-    return (102);
+    return set_error(p->error_handle, 102);
   if (index <= 0 || index > net->Nnodes)
-    return (203);
+    return set_error(p->error_handle, 203);
 
   EN_getnodetype(p, index, &nodeType);
 
@@ -4701,10 +4960,10 @@ int DLLEXPORT EN_deletenode(EN_Project *p, int index) {
 
   net->Nnodes--;
 
-  return (0);
+  return set_error(p->error_handle, 0);
 }
 
-int DLLEXPORT EN_getrule(EN_Project *pr, int index, int *nPremises, int *nTrueActions, int *nFalseActions, EN_API_FLOAT_TYPE *priority)
+int DLLEXPORT EN_getrule(EN_ProjectHandle ph, int index, int *nPremises, int *nTrueActions, int *nFalseActions, EN_API_FLOAT_TYPE *priority)
 /*----------------------------------------------------------------
 **  Input:   index  = index of the rule
 **           nPremises  = number of conditions (IF AND OR)
@@ -4720,10 +4979,12 @@ int DLLEXPORT EN_getrule(EN_Project *pr, int index, int *nPremises, int *nTrueAc
   Premise *p;
   Action *c;
   
+  EN_Project *pr = (EN_Project*)ph;
+
   EN_Network *net = &pr->network;
 
   if (index > net->Nrules)
-    return (257);
+    return set_error(pr->error_handle, 257);
   *priority = (EN_API_FLOAT_TYPE)pr->rules.Rule[index].priority;
   count = 1;
   p = pr->rules.Rule[index].Pchain;
@@ -4750,24 +5011,24 @@ int DLLEXPORT EN_getrule(EN_Project *pr, int index, int *nPremises, int *nTrueAc
     }
   }
   *nFalseActions = count;
-  return (0);
+  return set_error(pr->error_handle, 0);
 }
 
-int DLLEXPORT EN_getpremise(EN_Project *pr, int indexRule, int idxPremise, int *logop,
+int DLLEXPORT EN_getpremise(EN_ProjectHandle ph, int indexRule, int idxPremise, int *logop,
                            int *object, int *indexObj, int *variable,
                            int *relop, int *status, EN_API_FLOAT_TYPE *value) {
   int count = 1, error = 0, nPremises, a, b;
   EN_API_FLOAT_TYPE priority;
   Premise *p;
   
-  
+  EN_Project *pr = (EN_Project*)ph;
   
   if (indexRule > pr->network.Nrules) {
-    return (257);
+    return set_error(pr->error_handle, 257);
   }
   error = EN_getrule(pr, indexRule, &nPremises, &a, &b, &priority);
   if (idxPremise > nPremises) {
-    return (258);
+    return set_error(pr->error_handle, 258);
   }
   
   p = pr->rules.Rule[indexRule].Pchain;
@@ -4782,10 +5043,10 @@ int DLLEXPORT EN_getpremise(EN_Project *pr, int indexRule, int idxPremise, int *
   *relop = p->relop;
   *status = p->status;
   *value = (EN_API_FLOAT_TYPE)p[0].value;
-  return (0);
+  return set_error(pr->error_handle, 0);
 }
 
-int DLLEXPORT EN_setrulepriority(EN_Project *pr, int index, EN_API_FLOAT_TYPE priority)
+int DLLEXPORT EN_setrulepriority(EN_ProjectHandle ph, int index, EN_API_FLOAT_TYPE priority)
 /*----------------------------------------------------------------
 **  Input:   index  = index of the rule
 **           priority = rule priority
@@ -4794,29 +5055,32 @@ int DLLEXPORT EN_setrulepriority(EN_Project *pr, int index, EN_API_FLOAT_TYPE pr
 **----------------------------------------------------------------
 */
 {
+  EN_Project *pr = (EN_Project*)ph;
+
   if (index > pr->network.Nrules) {
-    return (257);
+    return set_error(pr->error_handle, 257);
   }
   pr->rules.Rule[index].priority = priority;
 
-  return (0);
+  return set_error(pr->error_handle, 0);
 }
 
-int DLLEXPORT EN_setpremise(EN_Project *pr, int indexRule, int indexPremise, int logop,
+int DLLEXPORT EN_setpremise(EN_ProjectHandle ph, int indexRule, int indexPremise, int logop,
                            int object, int indexObj, int variable, int relop,
                            int status, EN_API_FLOAT_TYPE value) {
   int count = 1, error = 0, nPremises, a, b;
   EN_API_FLOAT_TYPE priority;
   Premise *p;
   
-  
+  EN_Project *pr;
+  pr = (EN_Project*)ph;
 
   if (indexRule > pr->network.Nrules) {
-    return (257);
+    return set_error(pr->error_handle, 257);
   }
   error = EN_getrule(pr, indexRule, &nPremises, &a, &b, &priority);
   if (indexPremise > nPremises) {
-    return (258);
+    return set_error(pr->error_handle, 258);
   }
   p = pr->rules.Rule[indexRule].Pchain;
   while (count < indexPremise) {
@@ -4830,19 +5094,21 @@ int DLLEXPORT EN_setpremise(EN_Project *pr, int indexRule, int indexPremise, int
   p->relop = relop;
   p->status = status;
   p->value = value;
-  return (0);
+  return set_error(pr->error_handle, 0);
 }
 
-int DLLEXPORT EN_setpremiseindex(EN_Project *pr, int indexRule, int indexPremise, int indexObj) {
+int DLLEXPORT EN_setpremiseindex(EN_ProjectHandle ph, int indexRule, int indexPremise, int indexObj) {
   int count = 1, error = 0, nPremises, a, b;
   EN_API_FLOAT_TYPE priority;
   Premise *p;
 
+  EN_Project *pr = (EN_Project*)ph;
+
   if (indexRule > pr->network.Nrules)
-    return (257);
+    return set_error(pr->error_handle, 257);
   error = EN_getrule(pr, indexRule, &nPremises, &a, &b, &priority);
   if (indexPremise > nPremises) {
-    return (258);
+    return set_error(pr->error_handle, 258);
   }
   p = pr->rules.Rule[indexRule].Pchain;
   while (count < indexPremise) {
@@ -4850,20 +5116,22 @@ int DLLEXPORT EN_setpremiseindex(EN_Project *pr, int indexRule, int indexPremise
     p = p->next;
   }
   p->index = indexObj;
-  return (0);
+  return set_error(pr->error_handle, 0);
 }
 
-int DLLEXPORT EN_setpremisestatus(EN_Project *pr, int indexRule, int indexPremise, int status) {
+int DLLEXPORT EN_setpremisestatus(EN_ProjectHandle ph, int indexRule, int indexPremise, int status) {
   int count = 1, error = 0, nPremises, a, b;
   EN_API_FLOAT_TYPE priority;
   Premise *p;
 
+  EN_Project *pr = (EN_Project*)ph;
+
   if (indexRule > pr->network.Nrules) {
-    return (257);
+    return set_error(pr->error_handle, 257);
   }
   error = EN_getrule(pr, indexRule, &nPremises, &a, &b, &priority);
   if (indexPremise > nPremises) {
-    return (258);
+    return set_error(pr->error_handle, 258);
   }
   p = pr->rules.Rule[indexRule].Pchain;
   while (count < indexPremise) {
@@ -4871,20 +5139,22 @@ int DLLEXPORT EN_setpremisestatus(EN_Project *pr, int indexRule, int indexPremis
     p = p->next;
   }
   p->status = status;
-  return (0);
+  return set_error(pr->error_handle, 0);
 }
 
-int DLLEXPORT EN_setpremisevalue(EN_Project *pr, int indexRule, int indexPremise,
+int DLLEXPORT EN_setpremisevalue(EN_ProjectHandle ph, int indexRule, int indexPremise,
                                 EN_API_FLOAT_TYPE value) {
   int count = 1, error = 0, nPremises, a, b;
   EN_API_FLOAT_TYPE priority;
   Premise *p;
 
+  EN_Project *pr = (EN_Project*)ph;
+
   if (indexRule > pr->network.Nrules)
-    return (257);
+    return set_error(pr->error_handle, 257);
   error = EN_getrule(pr, indexRule, &nPremises, &a, &b, &priority);
   if (indexPremise > nPremises) {
-    return (258);
+    return set_error(pr->error_handle, 258);
   }
   p = pr->rules.Rule[indexRule].Pchain;
   while (count < indexPremise) {
@@ -4892,21 +5162,23 @@ int DLLEXPORT EN_setpremisevalue(EN_Project *pr, int indexRule, int indexPremise
     p = p->next;
   }
   p->value = value;
-  return (0);
+  return set_error(pr->error_handle, 0);
 }
 
-int DLLEXPORT EN_gettrueaction(EN_Project *pr, int indexRule, int indexAction, int *indexLink,
+int DLLEXPORT EN_gettrueaction(EN_ProjectHandle ph, int indexRule, int indexAction, int *indexLink,
                               int *status, EN_API_FLOAT_TYPE *setting) {
   int count = 1, error = 0, nTrueAction, c, b;
   EN_API_FLOAT_TYPE priority;
   Action *a;
 
+  EN_Project *pr = (EN_Project*)ph;
+
   if (indexRule > pr->network.Nrules) {
-    return (252);
+    return set_error(pr->error_handle, 252);
   }
   error = EN_getrule(pr, indexRule, &c, &nTrueAction, &b, &priority);
   if (indexAction > nTrueAction) {
-    return (253);
+    return set_error(pr->error_handle, 253);
   }
   a = pr->rules.Rule[indexRule].Tchain;
   while (count < indexAction) {
@@ -4916,21 +5188,23 @@ int DLLEXPORT EN_gettrueaction(EN_Project *pr, int indexRule, int indexAction, i
   *indexLink = a->link;
   *status = a->status;
   *setting = (EN_API_FLOAT_TYPE)a->setting;
-  return (0);
+  return set_error(pr->error_handle, 0);
 }
 
-int DLLEXPORT EN_settrueaction(EN_Project *pr, int indexRule, int indexAction, int indexLink,
+int DLLEXPORT EN_settrueaction(EN_ProjectHandle ph, int indexRule, int indexAction, int indexLink,
                               int status, EN_API_FLOAT_TYPE setting) {
   int count = 1, error = 0, nTrueAction, c, b;
   EN_API_FLOAT_TYPE priority;
   Action *a;
 
+  EN_Project *pr = (EN_Project*)ph;
+
   if (indexRule > pr->network.Nrules) {
-    return (257);
+    return set_error(pr->error_handle, 257);
   }
   error = EN_getrule(pr, indexRule, &c, &nTrueAction, &b, &priority);
   if (indexAction > nTrueAction) {
-    return (258);
+    return set_error(pr->error_handle, 258);
   }
   a = pr->rules.Rule[indexRule].Tchain;
   while (count < indexAction) {
@@ -4940,21 +5214,23 @@ int DLLEXPORT EN_settrueaction(EN_Project *pr, int indexRule, int indexAction, i
   a->link = indexLink;
   a->status = status;
   a->setting = setting;
-  return (0);
+  return set_error(pr->error_handle, 0);
 }
 
-int DLLEXPORT EN_getfalseaction(EN_Project *pr, int indexRule, int indexAction, int *indexLink,
+int DLLEXPORT EN_getfalseaction(EN_ProjectHandle ph, int indexRule, int indexAction, int *indexLink,
                                int *status, EN_API_FLOAT_TYPE *setting) {
   int count = 1, error = 0, nFalseAction, c, b;
   EN_API_FLOAT_TYPE priority;
   Action *a;
 
+  EN_Project *pr = (EN_Project*)ph;
+
   if (indexRule > pr->network.Nrules) {
-    return (257);
+    return set_error(pr->error_handle, 257);
   }
   error = EN_getrule(pr, indexRule, &c, &b, &nFalseAction, &priority);
   if (indexAction > nFalseAction) {
-    return (258);
+    return set_error(pr->error_handle, 258);
   }
   a = pr->rules.Rule[indexRule].Fchain;
   while (count < indexAction) {
@@ -4964,21 +5240,23 @@ int DLLEXPORT EN_getfalseaction(EN_Project *pr, int indexRule, int indexAction,
   *indexLink = a->link;
   *status = a->status;
   *setting = (EN_API_FLOAT_TYPE)a->setting;
-  return (0);
+  return set_error(pr->error_handle, 0);
 }
 
-int DLLEXPORT EN_setfalseaction(EN_Project *pr, int indexRule, int indexAction, int indexLink,
+int DLLEXPORT EN_setfalseaction(EN_ProjectHandle ph, int indexRule, int indexAction, int indexLink,
                                int status, EN_API_FLOAT_TYPE setting) {
   int count = 1, error = 0, nFalseAction, c, b;
   EN_API_FLOAT_TYPE priority;
   Action *a;
 
+  EN_Project *pr = (EN_Project*)ph;
+
   if (indexRule > pr->network.Nrules) {
-    return (257);
+    return set_error(pr->error_handle, 257);
   }
   error = EN_getrule(pr, indexRule, &c, &b, &nFalseAction, &priority);
   if (indexAction > nFalseAction) {
-    return (258);
+    return set_error(pr->error_handle, 258);
   }
   a = pr->rules.Rule[indexRule].Fchain;
   while (count < indexAction) {
@@ -4989,17 +5267,20 @@ int DLLEXPORT EN_setfalseaction(EN_Project *pr, int indexRule, int indexAction,
   a->status = status;
   a->setting = setting;
 
-  return (0);
+  return set_error(pr->error_handle, 0);
 }
 
-int DLLEXPORT EN_getruleID(EN_Project *pr, int indexRule, char *id) {
+int DLLEXPORT EN_getruleID(EN_ProjectHandle ph, int indexRule, char *id) {
+
+  EN_Project *pr = (EN_Project*)ph;
+
   strcpy(id, "");
   if (!pr->Openflag)
-    return (102);
+    return set_error(pr->error_handle, 102);
   if (indexRule < 1 || indexRule > pr->network.Nrules)
-    return (257);
+    return set_error(pr->error_handle, 257);
   strcpy(id, pr->rules.Rule[indexRule].label);
-  return (0);
+  return set_error(pr->error_handle, 0);
 }
 
 /*************************** END OF EPANET.C ***************************/
diff --git a/src/funcs.h b/src/funcs.h
index e274ded..b961a82 100755
--- a/src/funcs.h
+++ b/src/funcs.h
@@ -36,10 +36,11 @@ int     allocdata(EN_Project *pr);                 /* Allocates memory
 void    freeTmplist(STmplist *);                   /* Frees items in linked list */
 void    freeFloatlist(SFloatlist *);               /* Frees list of floats       */
 void    freedata(EN_Project *pr);                  /* Frees allocated memory     */
-int     openfiles(EN_Project *pr, char *,char *,char *);  /* Opens input & report files */
+int     openfiles(EN_Project *pr, const char *, 
+        const char *,const char *);                /* Opens input & report files */
 int     openhydfile(EN_Project *pr);               /* Opens hydraulics file      */
 int     openoutfile(EN_Project *pr);               /* Opens binary output file   */
-int     strcomp(char *, char *);                   /* Compares two strings       */
+int     strcomp(const char *, const char *);       /* Compares two strings       */
 char*   getTmpName(EN_Project *p, char* fname);    /* Gets temporary file name   */     
 double  interp(int n, double x[], double y[],
         double xx);                                /* Interpolates a data curve  */
@@ -51,7 +52,7 @@ int     findvalve(EN_Network *n, int);             /* Find valve index from node
 int     findpump(EN_Network *n, int);              /* Find pump index from node index */  // (AH)
 char   *geterrmsg(int errcode, char *msg);         /* Gets text of error message */
 void    errmsg(EN_Project *p, int);                /* Reports program error      */
-void    writecon(char *);                          /* Writes text to console     */
+void    writecon(const char *);                    /* Writes text to console     */
 void    writewin(void (*vp)(char *), char *);      /* Passes text to calling app */
 
 /* ------- INPUT1.C --------------------*/
@@ -126,6 +127,8 @@ void    freerules(EN_Project *pr);                  /* Frees rule base memory
 int     writeRuleinInp(EN_Project *pr, FILE *f,     /* Writes rule to an INP file */
                       int RuleIdx);
 
+int     writeRuleinInp(EN_Project *pr, FILE *f, int RuleIdx);
+
 /* ------------- REPORT.C --------------*/
 int     writereport(EN_Project *pr);                /* Writes formatted report    */
 void    writelogo(EN_Project *pr);                  /* Writes program logo        */
diff --git a/src/input2.c b/src/input2.c
index e4836b5..c40d029 100644
--- a/src/input2.c
+++ b/src/input2.c
@@ -820,9 +820,10 @@ int match(const char *str, const char *substr)
       break;
 
   /* Check if substr matches remainder of str. */
-  for (i = i, j = 0; substr[j]; i++, j++)
+  for (j = 0; substr[j]; i++, j++)
     if (!str[i] || UCHAR(str[i]) != UCHAR(substr[j]))
       return (0);
+
   return (1);
 } /* end of match */
 
diff --git a/src/rules.c b/src/rules.c
index d5da392..b8d0518 100644
--- a/src/rules.c
+++ b/src/rules.c
@@ -112,7 +112,7 @@ int takeactions(EN_Project *pr);
 void clearactlist(rules_t *rules);
 void clearrules(EN_Project *pr);
 void ruleerrmsg(EN_Project *pr, int);
-int writeRuleinInp(EN_Project *pr, FILE *f, int RuleIdx);
+//int writeRuleinInp(EN_Project *pr, FILE *f, int RuleIdx);
 
 void initrules(rules_t *rules)
 /*
diff --git a/src/types.h b/src/types.h
index c520280..d887c96 100755
--- a/src/types.h
+++ b/src/types.h
@@ -23,6 +23,8 @@ AUTHOR:     L. Rossman
 #include "epanet2.h"
 #include "hash.h"
 #include "mempool.h"
+#include "util/errormanager.h"
+
 
 /*********************************************************/
 /* All floats have been re-declared as doubles (7/3/07). */
@@ -861,7 +863,7 @@ typedef struct {
 
 
 /* project wrapper */
-struct EN_Project {
+typedef struct EN_Project {
   
   EN_Network network; /// the network description struct
   hydraulics_t hydraulics;
@@ -883,8 +885,10 @@ struct EN_Project {
   Title[MAXTITLE][MAXMSG+1],  /// Problem title
   MapFname[MAXFNAME+1];       /// Map file name
   
+  error_handle_t* error_handle; //Simple error manager
+
   void (* viewprog) (char *);     /* Pointer to progress viewing function */   
   
-};
+} EN_Project;
 
 #endif
diff --git a/src/util/errormanager.c b/src/util/errormanager.c
new file mode 100644
index 0000000..abba233
--- /dev/null
+++ b/src/util/errormanager.c
@@ -0,0 +1,73 @@
+//-----------------------------------------------------------------------------
+//
+//   errormanager.c
+//
+//   Purpose: Provides a simple interface for managing runtime error messages.
+//
+//   Date:       08/25/2017
+//
+//   Author:     Michael E. Tryby
+//               US EPA - ORD/NRMRL
+//-----------------------------------------------------------------------------
+#include "errormanager.h"
+
+error_handle_t* new_errormanager(void (*p_error_message)(int, char*, int))
+//
+// Purpose: Constructs a new error handle.
+//
+{
+    error_handle_t* error_handle;
+    error_handle = (error_handle_t*)calloc(1, sizeof(error_handle_t));
+
+	if (error_handle != NULL)
+		error_handle->p_msg_lookup = p_error_message;
+
+    return error_handle;
+}
+
+void dst_errormanager(error_handle_t* error_handle)
+//
+// Purpose: Destroys the error handle.
+//
+{
+    free(error_handle);
+}
+
+int set_error(error_handle_t* error_handle, int errorcode)
+//
+// Purpose: Sets an error code in the handle.
+//
+{
+    // If the error code is 0 no action is taken and 0 is returned.
+    // This is a feature not a bug.
+    if (errorcode)
+        error_handle->error_status = errorcode;
+
+    return errorcode;
+}
+
+char* check_error(error_handle_t* error_handle)
+//
+// Purpose: Returns the error message or NULL.
+//
+// Note: Caller must free memory allocated by check_error
+//
+{
+    char* temp = NULL;
+
+    if (error_handle->error_status != 0) {
+        temp = (char*) calloc(ERR_MAXMSG, sizeof(char));
+
+        if (temp)
+            error_handle->p_msg_lookup(error_handle->error_status, temp, ERR_MAXMSG);
+    }
+    return temp;
+}
+
+void clear_error(error_handle_t* error_handle)
+//
+// Purpose: Clears the error from the handle.
+//
+{
+    error_handle->error_status = 0;
+}
diff --git a/src/util/errormanager.h b/src/util/errormanager.h
new file mode 100644
index 0000000..36ee969
--- /dev/null
+++ b/src/util/errormanager.h
@@ -0,0 +1,30 @@
+/*
+ *  errormanager.h
+ *
+ *  Created on: Aug 25, 2017
+ *
+ *      Author: Michael E. Tryby
+ *              US EPA - ORD/NRMRL
+ */
+
+#ifndef ERRORMANAGER_H_
+#define ERRORMANAGER_H_
+
+#include <stdlib.h>
+#include <string.h>
+
+#define ERR_MAXMSG 256
+
+typedef struct error_s {
+    int error_status;
+    void (*p_msg_lookup)(int, char*, int);
+} error_handle_t;
+
+error_handle_t* new_errormanager(void (*p_error_message)(int, char*, int));
+void dst_errormanager(error_handle_t* error_handle);
+
+int set_error(error_handle_t* error_handle, int errorcode);
+char* check_error(error_handle_t* error_handle);
+void clear_error(error_handle_t* error_handle);
+
+#endif /* ERRORMANAGER_H_ */
diff --git a/src/vars.h b/src/vars.h
index 04f540c..9c4c08f 100755
--- a/src/vars.h
+++ b/src/vars.h
@@ -11,6 +11,6 @@
 
 // this single global variable is used only when the library is called in "legacy mode"
 // with the 2.1-style API. 
-EXTERN EN_Project *_defaultModel;
+EXTERN void *_defaultModel;
 
 #endif
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 609d0b4..be6dc5a 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -37,8 +37,7 @@ foreach(testSrc ${TEST_SRCS})
         #link to Boost libraries AND your targets and dependencies
         target_link_libraries(${testName} ${Boost_LIBRARIES} epanet epanet-output)
 
-
-        #Finally add it to test execution - 
+        #Finally add it to test execution
         #Notice the WORKING_DIRECTORY and COMMAND
         add_test(NAME ${testName}
                  COMMAND ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/${testName}  
diff --git a/tests/data/example1.out b/tests/data/example1.out
new file mode 100644
index 0000000..416c98b
Binary files /dev/null and b/tests/data/example1.out differ
diff --git a/tests/data/net1.inp b/tests/data/net1.inp
new file mode 100644
index 0000000..4df5bbf
--- /dev/null
+++ b/tests/data/net1.inp
@@ -0,0 +1,178 @@
+[TITLE]
+ EPANET Example Network 1
+A simple example of modeling chlorine decay. Both bulk and
+wall reactions are included. 
+
+[JUNCTIONS]
+;ID              	Elev        	Demand      	Pattern         
+ 10              	710         	0           	                	;
+ 11              	710         	150         	                	;
+ 12              	700         	150         	                	;
+ 13              	695         	100         	                	;
+ 21              	700         	150         	                	;
+ 22              	695         	200         	                	;
+ 23              	690         	150         	                	;
+ 31              	700         	100         	                	;
+ 32              	710         	100         	                	;
+
+[RESERVOIRS]
+;ID              	Head        	Pattern         
+ 9               	800         	                	;
+
+[TANKS]
+;ID              	Elevation   	InitLevel   	MinLevel    	MaxLevel    	Diameter    	MinVol      	VolCurve
+ 2               	850         	120         	100         	150         	50.5        	0           	                	;
+
+[PIPES]
+;ID              	Node1           	Node2           	Length      	Diameter    	Roughness   	MinorLoss   	Status
+ 10              	10              	11              	10530       	18          	100         	0           	Open  	;
+ 11              	11              	12              	5280        	14          	100         	0           	Open  	;
+ 12              	12              	13              	5280        	10          	100         	0           	Open  	;
+ 21              	21              	22              	5280        	10          	100         	0           	Open  	;
+ 22              	22              	23              	5280        	12          	100         	0           	Open  	;
+ 31              	31              	32              	5280        	6           	100         	0           	Open  	;
+ 110             	2               	12              	200         	18          	100         	0           	Open  	;
+ 111             	11              	21              	5280        	10          	100         	0           	Open  	;
+ 112             	12              	22              	5280        	12          	100         	0           	Open  	;
+ 113             	13              	23              	5280        	8           	100         	0           	Open  	;
+ 121             	21              	31              	5280        	8           	100         	0           	Open  	;
+ 122             	22              	32              	5280        	6           	100         	0           	Open  	;
+
+[PUMPS]
+;ID              	Node1           	Node2           	Parameters
+ 9               	9               	10              	HEAD 1	;
+
+[VALVES]
+;ID              	Node1           	Node2           	Diameter    	Type	Setting     	MinorLoss   
+
+[TAGS]
+
+[DEMANDS]
+;Junction        	Demand      	Pattern         	Category
+
+[STATUS]
+;ID              	Status/Setting
+
+[PATTERNS]
+;ID              	Multipliers
+;Demand Pattern
+ 1               	1.0         	1.2         	1.4         	1.6         	1.4         	1.2         
+ 1               	1.0         	0.8         	0.6         	0.4         	0.6         	0.8         
+
+[CURVES]
+;ID              	X-Value     	Y-Value
+;PUMP: Pump Curve for Pump 9
+ 1               	1500        	250         
+
+[CONTROLS]
+ LINK 9 OPEN IF NODE 2 BELOW 110
+ LINK 9 CLOSED IF NODE 2 ABOVE 140
+
+
+[RULES]
+
+[ENERGY]
+ Global Efficiency  	75
+ Global Price       	0.0
+ Demand Charge      	0.0
+
+[EMITTERS]
+;Junction        	Coefficient
+
+[QUALITY]
+;Node            	InitQual
+ 10              	0.5
+ 11              	0.5
+ 12              	0.5
+ 13              	0.5
+ 21              	0.5
+ 22              	0.5
+ 23              	0.5
+ 31              	0.5
+ 32              	0.5
+ 9               	1.0
+ 2               	1.0
+
+[SOURCES]
+;Node            	Type        	Quality     	Pattern
+
+[REACTIONS]
+;Type     	Pipe/Tank       	Coefficient
+
+
+[REACTIONS]
+ Order Bulk            	1
+ Order Tank            	1
+ Order Wall            	1
+ Global Bulk           	-.5
+ Global Wall           	-1
+ Limiting Potential    	0.0
+ Roughness Correlation 	0.0
+
+[MIXING]
+;Tank            	Model
+
+[TIMES]
+ Duration           	24:00 
+ Hydraulic Timestep 	1:00 
+ Quality Timestep   	0:05 
+ Pattern Timestep   	2:00 
+ Pattern Start      	0:00 
+ Report Timestep    	1:00 
+ Report Start       	0:00 
+ Start ClockTime    	12 am
+ Statistic          	None
+
+[REPORT]
+ Status             	Yes
+ Summary            	No
+ Page               	0
+
+[OPTIONS]
+ Units              	GPM
+ Headloss           	H-W
+ Specific Gravity   	1.0
+ Viscosity          	1.0
+ Trials             	40
+ Accuracy           	0.001
+ CHECKFREQ          	2
+ MAXCHECK           	10
+ DAMPLIMIT          	0
+ Unbalanced         	Continue 10
+ Pattern            	1
+ Demand Multiplier  	1.0
+ Emitter Exponent   	0.5
+ Quality            	Chlorine mg/L
+ Diffusivity        	1.0
+ Tolerance          	0.01
+
+[COORDINATES]
+;Node            	X-Coord         	Y-Coord
+ 10              	20.00           	70.00           
+ 11              	30.00           	70.00           
+ 12              	50.00           	70.00           
+ 13              	70.00           	70.00           
+ 21              	30.00           	40.00           
+ 22              	50.00           	40.00           
+ 23              	70.00           	40.00           
+ 31              	30.00           	10.00           
+ 32              	50.00           	10.00           
+ 9               	10.00           	70.00           
+ 2               	50.00           	90.00           
+
+[VERTICES]
+;Link            	X-Coord         	Y-Coord
+
+[LABELS]
+;X-Coord           Y-Coord          Label & Anchor Node
+ 6.99             73.63            "Source"                 
+ 13.48            68.13            "Pump"                 
+ 43.85            91.21            "Tank"                 
+
+[BACKDROP]
+ DIMENSIONS     	7.00            	6.00            	73.00           	94.00           
+ UNITS          	None
+ FILE           	
+ OFFSET         	0.00            	0.00            
+
+[END]
diff --git a/tests/test_output.cpp b/tests/test_output.cpp
index cd55f4f..78f55ed 100644
--- a/tests/test_output.cpp
+++ b/tests/test_output.cpp
@@ -22,8 +22,7 @@
 
 #include "epanet_output.h"
 
-
-#define DATA_PATH "./net1.out"
+#define DATA_PATH "./example1.out"
 
 using namespace std; 
 
@@ -117,7 +116,6 @@ struct Fixture{
 
     float* array;
     int array_dim;
-
 };
 
 BOOST_AUTO_TEST_SUITE(test_output_fixture)
@@ -144,6 +142,15 @@ BOOST_FIXTURE_TEST_CASE(test_getNetSize, Fixture)
     ENR_free((void**)&i_array);
 }
 
+BOOST_FIXTURE_TEST_CASE(test_getUnits, Fixture) {
+    int flag;
+
+    error = ENR_getUnits(p_handle, ENR_qualUnits, &flag);
+	BOOST_REQUIRE(error == 0);
+
+	BOOST_CHECK_EQUAL(flag, ENR_MGL);
+}
+
 BOOST_FIXTURE_TEST_CASE(test_getElementName, Fixture) {
     char* name = new char[MAXID];
     int length, index = 1;
@@ -179,7 +186,6 @@ BOOST_FIXTURE_TEST_CASE(test_getNodeAttribute, Fixture) {
     std::vector<float> ref_vec;
     ref_vec.assign(ref_array, ref_array + ref_dim);
 
-
     std::vector<float> test_vec;
     test_vec.assign(array, array + array_dim);
 
diff --git a/tests/test_toolkit.cpp b/tests/test_toolkit.cpp
new file mode 100644
index 0000000..6ca6322
--- /dev/null
+++ b/tests/test_toolkit.cpp
@@ -0,0 +1,207 @@
+//
+// test_epanet_toolkit.cpp
+//
+// Date Created: January 24, 2018
+//
+// Author: Michael E. Tryby
+//         US EPA - ORD/NRMRL
+//
+
+//#define BOOST_TEST_DYN_LINK
+
+#define BOOST_TEST_MODULE "toolkit"
+#include <boost/test/included/unit_test.hpp>
+
+#include <string>
+#include "epanet2.h"
+
+// NOTE: Project Home needs to be updated to run unit test
+#define DATA_PATH_INP "./net1.inp"
+#define DATA_PATH_RPT "./test.rpt"
+#define DATA_PATH_OUT "./test.out"
+
+using namespace std;
+
+
+BOOST_AUTO_TEST_SUITE (test_toolkit)
+
+BOOST_AUTO_TEST_CASE (test_alloc_free)
+{
+    int error = 0;
+    EN_ProjectHandle ph = NULL;
+
+    error = EN_createproject(&ph);
+
+    BOOST_REQUIRE(error == 0);
+    BOOST_CHECK(ph != NULL);
+
+    error = EN_deleteproject(&ph);
+
+    BOOST_REQUIRE(error == 0);
+    BOOST_CHECK(ph == NULL);
+}
+
+BOOST_AUTO_TEST_CASE (test_open_close)
+{
+    EN_ProjectHandle ph = NULL;
+    EN_createproject(&ph);
+
+    std::string path_inp = std::string(DATA_PATH_INP);
+    std::string path_rpt = std::string(DATA_PATH_RPT);
+    std::string path_out = std::string(DATA_PATH_OUT);
+
+    int error = EN_open(ph, path_inp.c_str(), path_rpt.c_str(), path_out.c_str());
+    BOOST_REQUIRE(error == 0);
+
+    error = EN_close(ph);
+    BOOST_REQUIRE(error == 0);
+
+    EN_deleteproject(&ph);
+}
+
+BOOST_AUTO_TEST_CASE(test_epanet)
+{
+    std::string path_inp = std::string(DATA_PATH_INP);
+    std::string path_rpt = std::string(DATA_PATH_RPT);
+    std::string path_out = std::string(DATA_PATH_OUT);
+
+    int error = ENepanet(path_inp.c_str(), path_rpt.c_str(), path_out.c_str(), NULL);
+    BOOST_REQUIRE(error == 0);
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+
+struct Fixture{
+    Fixture() {
+        path_inp = std::string(DATA_PATH_INP);
+        path_rpt = std::string(DATA_PATH_RPT);
+        path_out = std::string(DATA_PATH_OUT);
+
+        EN_createproject(&ph);
+        error = EN_open(ph, path_inp.c_str(), path_rpt.c_str(), path_out.c_str());
+
+    }
+
+    ~Fixture() {
+      error = EN_close(ph);
+      EN_deleteproject(&ph);
+  }
+
+  std::string path_inp;
+  std::string path_rpt;
+  std::string path_out;
+
+  int error;
+  EN_ProjectHandle ph;
+
+};
+
+BOOST_AUTO_TEST_SUITE(test_epanet_fixture)
+
+BOOST_FIXTURE_TEST_CASE(test_epanet, Fixture)
+{
+    error = EN_solveH(ph);
+    BOOST_REQUIRE(error == 0);
+
+    error = EN_solveQ(ph);
+    BOOST_REQUIRE(error == 0);
+
+    error = EN_report(ph);
+    BOOST_REQUIRE(error == 0);
+}
+
+BOOST_FIXTURE_TEST_CASE(test_hyd_step, Fixture)
+{
+    int flag = 00;
+    long t, tstep;
+
+    error = EN_openH(ph);
+    BOOST_REQUIRE(error == 0);
+
+    error = EN_initH(ph, flag);
+    BOOST_REQUIRE(error == 0);
+
+    do {
+        error = EN_runH(ph, &t);
+        BOOST_REQUIRE(error == 0);
+
+        error = EN_nextH(ph, &tstep);
+        BOOST_REQUIRE(error == 0);
+
+    } while (tstep > 0);
+    
+    error = EN_closeH(ph);
+    BOOST_REQUIRE(error == 0);
+}
+
+BOOST_FIXTURE_TEST_CASE(test_qual_step, Fixture)
+{
+    int flag = 0;
+    long t, tstep;
+
+    error = EN_solveH(ph);
+    BOOST_REQUIRE(error == 0);
+
+    error = EN_openQ(ph);
+    BOOST_REQUIRE(error == 0);
+
+    error = EN_initQ(ph, flag);
+    BOOST_REQUIRE(error == 0);
+
+    do {
+        error = EN_runQ(ph, &t);
+        BOOST_REQUIRE(error == 0);
+
+        error = EN_nextQ(ph, &tstep);
+        BOOST_REQUIRE(error == 0);
+
+    } while (tstep > 0);
+    
+    error = EN_closeQ(ph);
+    BOOST_REQUIRE(error == 0);
+}
+
+BOOST_FIXTURE_TEST_CASE(test_progressive_stepping, Fixture)
+{
+    int flag = EN_NOSAVE;
+    long t, tstep_h, tstep_q;
+
+    error = EN_openH(ph);
+    BOOST_REQUIRE(error == 0);
+
+    error = EN_initH(ph, flag);
+    BOOST_REQUIRE(error == 0);
+
+    error = EN_openQ(ph);
+    BOOST_REQUIRE(error == 0);
+
+    error = EN_initQ(ph, flag);
+    BOOST_REQUIRE(error == 0);
+
+    do {
+
+
+        error = EN_runH(ph, &t);
+        BOOST_REQUIRE(error == 0);
+
+        error = EN_runQ(ph, &t);
+        BOOST_REQUIRE(error == 0);
+
+        error = EN_nextH(ph, &tstep_h);
+        BOOST_REQUIRE(error == 0);
+
+        error = EN_nextQ(ph, &tstep_q);
+        BOOST_REQUIRE(error == 0);
+
+    } while (tstep_h > 0);
+
+    error = EN_closeH(ph);
+    BOOST_REQUIRE(error == 0);
+
+    error = EN_closeQ(ph);
+    BOOST_REQUIRE(error == 0);
+
+}
+
+BOOST_AUTO_TEST_SUITE_END()
diff --git a/tools/epanet-output/include/epanet_output.h b/tools/epanet-output/include/epanet_output.h
index 0066d16..93a8425 100644
--- a/tools/epanet-output/include/epanet_output.h
+++ b/tools/epanet-output/include/epanet_output.h
@@ -18,22 +18,42 @@
 typedef void* ENR_Handle;
 
 typedef enum {
-    ENR_node = 1,
-    ENR_link = 2
+    ENR_node        = 1,
+    ENR_link        = 2
 } ENR_ElementType;
 
 typedef enum {
-    ENR_getSeries    = 1,
-    ENR_getAttribute = 2,
-    ENR_getResult    = 3,
-    ENR_getReacts    = 4,
-    ENR_getEnergy    = 5
-} ENR_ApiFunction;
+    ENR_flowUnits   = 1,
+    ENR_pressUnits  = 2,
+    ENR_qualUnits   = 3
+} ENR_Units;
 
 typedef enum {
-    ENR_flowUnits   = 1,
-    ENR_pressUnits  = 2
-} ENR_Units;
+    ENR_CFS         = 0,
+    ENR_GPM         = 1,
+    ENR_MGD         = 2,
+    ENR_IMGD        = 3,
+    ENR_AFD         = 4,
+    ENR_LPS         = 5,
+    ENR_LPM         = 6,
+    ENR_MLD         = 7,
+    ENR_CMH         = 8,
+    ENR_CMD         = 9
+} ENR_FlowUnits;
+
+typedef enum {
+	ENR_PSI         = 0,
+	ENR_MTR         = 1,
+	ENR_KPA         = 2
+} ENR_PressUnits;
+
+typedef enum {
+    ENR_NONE        = 0,
+    ENR_MGL         = 1,
+    ENR_UGL         = 2,
+    ENR_HOURS       = 3,
+    ENR_PRCNT       = 4
+} ENR_QualUnits;
 
 typedef enum {
     ENR_reportStart = 1,
@@ -43,21 +63,21 @@ typedef enum {
 }ENR_Time;
 
 typedef enum {
-    ENR_demand   = 1,
-    ENR_head     = 2,
-    ENR_pressure = 3,
-    ENR_quality  = 4
+    ENR_demand      = 1,
+    ENR_head        = 2,
+    ENR_pressure    = 3,
+    ENR_quality     = 4
 } ENR_NodeAttribute;
 
 typedef enum {
-    ENR_flow         = 1,
-    ENR_velocity     = 2,
-    ENR_headloss     = 3,
-    ENR_avgQuality   = 4,
-    ENR_status       = 5,
-    ENR_setting      = 6,
-    ENR_rxRate       = 7,
-    ENR_frctnFctr    = 8
+    ENR_flow        = 1,
+    ENR_velocity    = 2,
+    ENR_headloss    = 3,
+    ENR_avgQuality  = 4,
+    ENR_status      = 5,
+    ENR_setting     = 6,
+    ENR_rxRate      = 7,
+    ENR_frctnFctr   = 8
 } ENR_LinkAttribute;
 
 
diff --git a/tools/epanet-output/src/epanet_output.c b/tools/epanet-output/src/epanet_output.c
index 486ef81..741304f 100644
--- a/tools/epanet-output/src/epanet_output.c
+++ b/tools/epanet-output/src/epanet_output.c
@@ -57,7 +57,8 @@
 
 #define MINNREC       14   // Minimum allowable number of records
 #define PROLOGUE     884   // Preliminary fixed length section of header
-#define MAXID_P1      32   // Max. # characters in ID name
+#define MAXID_P1      32   // EPANET max characters in ID name PLUS 1
+#define MAXMSG_P1     80   // EPANET max characters in message text PLUS 1
 
 #define NELEMENTTYPES  5   // Number of element types
 #define NENERGYRESULTS 6   // Number of energy results
@@ -303,6 +304,8 @@ int DLLEXPORT ENR_getUnits(ENR_Handle p_handle, ENR_Units code, int* unitFlag)
  */
 {
     int errorcode = 0;
+    F_OFF offset;
+    char temp[MAXID_P1];
     data_t* p_data;
 
     *unitFlag = -1;
@@ -315,15 +318,37 @@ int DLLEXPORT ENR_getUnits(ENR_Handle p_handle, ENR_Units code, int* unitFlag)
         switch (code)
         {
         case ENR_flowUnits:
-            fseek(p_data->file, 9*WORDSIZE, SEEK_SET);
+            _fseek(p_data->file, 9*WORDSIZE, SEEK_SET);
             fread(unitFlag, WORDSIZE, 1, p_data->file);
             break;
 
         case ENR_pressUnits:
-            fseek(p_data->file, 10*WORDSIZE, SEEK_SET);
+            _fseek(p_data->file, 10*WORDSIZE, SEEK_SET);
             fread(unitFlag, WORDSIZE, 1, p_data->file);
             break;
 
+        case ENR_qualUnits:
+            offset = 7*WORDSIZE;
+            _fseek(p_data->file, offset, SEEK_SET);
+            fread(unitFlag, WORDSIZE, 1, p_data->file);
+
+            if (*unitFlag == 0) *unitFlag = ENR_NONE;
+
+            else if (*unitFlag == 1) {
+                offset = 15*WORDSIZE + 3*MAXMSG_P1 + 2*(MAXFNAME+1) + MAXID_P1;
+                _fseek(p_data->file, offset, SEEK_SET);
+                fread(temp, MAXID_P1, 1, p_data->file);
+
+                if (!strcmp(temp, "mg/L")) *unitFlag = ENR_MGL;
+                else *unitFlag = ENR_UGL;
+            }
+
+            else if (*unitFlag == 2) *unitFlag = ENR_HOURS;
+
+            else *unitFlag = ENR_PRCNT;
+
+            break;
+
         default: errorcode = 421;
         }
     }
@@ -378,6 +403,12 @@ int DLLEXPORT ENR_getTimes(ENR_Handle p_handle, ENR_Time code, int* time)
     return set_error(p_data->error_handle, errorcode);
 }
 
+int DLLEXPORT ENR_getChemData(ENR_Handle p_handle, char** name, int* length)
+
+{
+    return 0;
+}
+
 int DLLEXPORT ENR_getElementName(ENR_Handle p_handle, ENR_ElementType type,
         int elementIndex, char** name, int* length)
 /*------------------------------------------------------------------------
@@ -815,7 +846,7 @@ void errorLookup(int errcode, char* dest_msg, int dest_len)
     default:  msg = ERRERR;
     }
 
-    strncpy(dest_msg, msg, MAXMSG);
+    strncpy(dest_msg, msg, MSG_MAXLEN);
 }
 
 int validateFile(ENR_Handle p_handle)
diff --git a/tools/epanet-output/src/messages.h b/tools/epanet-output/src/messages.h
index 78725a1..bc04a7d 100644
--- a/tools/epanet-output/src/messages.h
+++ b/tools/epanet-output/src/messages.h
@@ -10,7 +10,7 @@
 #ifndef MESSAGES_H_
 #define MESSAGES_H_
 /*------------------- Error Messages --------------------*/
-#define MAXMSG 53
+#define MSG_MAXLEN 53
 
 #define WARN10 "Warning: model run issued warnings"
 
diff --git a/tools/epanet-output/test/epanet_output_test.py b/tools/epanet-output/test/epanet_output_test.py
deleted file mode 100644
index fa23d62..0000000
--- a/tools/epanet-output/test/epanet_output_test.py
+++ /dev/null
@@ -1,102 +0,0 @@
-#
-#   epanet_output_test.py
-#
-#   Created: 11/8/2017
-#   Author: Michael E. Tryby
-#           US EPA - ORD/NRMRL
-#
-#   Unit testing for EPANET Output API using pytest.
-#
-
-import pytest
-import numpy as np
-
-import epanet_output as oapi
-
-from data import OUTPUT_FILE_EXAMPLE1
-    
-@pytest.fixture()
-def enr_handle(request):    
-    _handle = oapi.enr_init()
-    oapi.enr_open(_handle, OUTPUT_FILE_EXAMPLE1)
-    
-    def enr_close():
-        oapi.enr_close()
-    
-    request.addfinalizer(enr_close)    
-    return _handle    
-
-
-def test_get_times(enr_handle):
-    num_periods = oapi.enr_get_times(enr_handle, oapi.Time.NUM_PERIODS)
-    assert num_periods == 25
-
-
-# def test_get_size(file_path):
-#     handle = oapi.enr_init()
-#     oapi.enr_open(handle, file_path)
-#     
-#     size = oapi.enr_get_net_size(handle)
-#     
-#     print(size)
-#     
-#     handle = oapi.enr_close()
-#                     
-# def test_get_names(file_path):
-#     handle = oapi.enr_init()
-#     oapi.enr_open(handle, file_path)
-#     
-#     name = oapi.enr_get_element_name(handle, oapi.ElementType.NODE, 10)
-#     
-#     print(name)
-#     
-#     handle = oapi.enr_close()        
-# 
-# def test_get_energy(file_path):
-#     handle = oapi.enr_init()
-#     oapi.enr_open(handle, file_path)
-#     
-#     result = oapi.enr_get_energy_usage(handle, 1)
-#     
-#     print(result)
-#     
-#     handle = oapi.enr_close()
-#     
-# def test_get_react(file_path):
-#     handle = oapi.enr_init()
-#     oapi.enr_open(handle, file_path)
-#     
-#     result = oapi.enr_get_net_reacts(handle)
-#     
-#     print(result)
-#     
-#     handle = oapi.enr_close()     
-#     
-def test_get_node_attribute(enr_handle):
-    ref_array = np.array([ 1., 0.44407997, 0.43766347, 0.42827705, 0.41342604, 
-        0.42804748, 0.44152543, 0.40502965, 0.38635802, 1., 0.96745253])
-
-    array = oapi.enr_get_node_attribute(enr_handle, 1, oapi.NodeAttribute.QUALITY)
-    assert len(array) == 11
-    assert np.allclose(array, ref_array)
- 
-def test_get_link_attribute(enr_handle):
-    ref_array = np.array([ 1848.58117676, 1220.42736816, 130.11161804, 
-        187.68930054, 119.88839722, 40.46448898, -748.58111572, 478.15377808, 
-        191.73458862, 30.11160851, 140.4644928, 59.53551483, 1848.58117676])
-    
-    array = oapi.enr_get_link_attribute(enr_handle, 1, oapi.LinkAttribute.FLOW)
-    assert len(array) == 13             
-    assert np.allclose(array, ref_array)
-     
-# if __name__ == "__main__":
-#     
-#     file_path = "M:\\net mydocuments\\EPA Projects\\EPAnet Examples\\net1.out"
-#     test_get_times(file_path)
-#     test_get_size(file_path)
-#     test_get_names(file_path)
-#     test_get_energy(file_path)
-#     test_get_react(file_path)
-#     test_get_node_attribute(file_path)
-#     test_get_link_attribute(file_path)
-#     
\ No newline at end of file
diff --git a/win_build/WinSDK/Makefile.bat b/win_build/WinSDK/Makefile.bat
index ee5b030..66bf58f 100644
--- a/win_build/WinSDK/Makefile.bat
+++ b/win_build/WinSDK/Makefile.bat
@@ -21,9 +21,9 @@ Find /i "x86" < checkOS.tmp > StringCheck.tmp
 If %ERRORLEVEL% == 1 (
 	CALL "%SDK_PATH%bin\"SetEnv.cmd /x64 /release
 	rem : create EPANET2.DLL
-	cl -o epanet2.dll epanet.c hash.c hydraul.c hydcoeffs.c hydsolver.c hydstatus.c genmmd.c inpfile.c input1.c input2.c input3.c mempool.c output.c quality.c report.c rules.c smatrix.c /I ..\include /I ..\run /link /DLL 
+	cl -o epanet2.dll epanet.c util\errormanager.c hash.c hydraul.c hydcoeffs.c hydsolver.c inpfile.c input1.c input2.c input3.c mempool.c output.c quality.c report.c rules.c smatrix.c genmmd.c /I ..\include /I ..\run /link /DLL 
 	rem : create EPANET2.EXE
-	cl -o epanet2.exe epanet.c ..\run\main.c hash.c hydraul.c hydcoeffs.c hydsolver.c hydstatus.c genmmd.c inpfile.c input1.c input2.c input3.c mempool.c output.c quality.c report.c rules.c smatrix.c /I ..\include /I ..\run /I ..\src /link
+	cl -o epanet2.exe epanet.c util\errormanager.c ..\run\main.c hash.c hydraul.c hydcoeffs.c hydsolver.c inpfile.c input1.c input2.c input3.c mempool.c output.c quality.c report.c rules.c smatrix.c genmmd.c /I ..\include /I ..\run /I ..\src /link
 	md "%Build_PATH%"\64bit
 	move /y "%SRC_PATH%"\*.dll "%Build_PATH%"\64bit
 	move /y "%SRC_PATH%"\*.exe "%Build_PATH%"\64bit
@@ -35,9 +35,9 @@ rem : 32 bit with DEF
 CALL "%SDK_PATH%bin\"SetEnv.cmd /x86 /release
 echo "32 bit with epanet2.def mapping"
 rem : create EPANET2.DLL
-cl -o epanet2.dll epanet.c hash.c hydraul.c hydcoeffs.c hydsolver.c hydstatus.c genmmd.c inpfile.c input1.c input2.c input3.c mempool.c output.c quality.c report.c rules.c smatrix.c /I ..\include /I ..\run /link /DLL /def:..\win_build\WinSDK\epanet2.def /MAP
+cl -o epanet2.dll epanet.c util\errormanager.c hash.c hydraul.c hydcoeffs.c hydsolver.c inpfile.c input1.c input2.c input3.c mempool.c output.c quality.c report.c rules.c smatrix.c genmmd.c /I ..\include /I ..\run /link /DLL /def:..\win_build\WinSDK\epanet2.def /MAP
 rem : create EPANET2.EXE
-cl -o epanet2.exe epanet.c ..\run\main.c hash.c hydraul.c hydcoeffs.c hydstatus.c genmmd.c hydsolver.c inpfile.c input1.c input2.c input3.c mempool.c output.c quality.c report.c rules.c smatrix.c /I ..\include /I ..\run /I ..\src /link
+cl -o epanet2.exe epanet.c util\errormanager.c ..\run\main.c hash.c hydraul.c hydcoeffs.c hydsolver.c inpfile.c input1.c input2.c input3.c mempool.c output.c quality.c report.c rules.c smatrix.c genmmd.c /I ..\include /I ..\run /I ..\src /link
 md "%Build_PATH%"\32bit
 move /y "%SRC_PATH%"\*.dll "%Build_PATH%"\32bit
 move /y "%SRC_PATH%"\*.exe "%Build_PATH%"\32bit
@@ -51,4 +51,3 @@ del "%SRC_PATH%"\*.map
 del "%SRC_PATH%"\*.tmp
 
 cd "%Build_PATH%"
-