Index: generic/nsfError.c
===================================================================
diff -u -rf0295d889aaf71709c63243685897dc3f11048f1 -r87c6a11296ada89c007cc2ed33df6887ac53c740
--- generic/nsfError.c	(.../nsfError.c)	(revision f0295d889aaf71709c63243685897dc3f11048f1)
+++ generic/nsfError.c	(.../nsfError.c)	(revision 87c6a11296ada89c007cc2ed33df6887ac53c740)
@@ -133,23 +133,23 @@
   return TCL_ERROR;
 }
 
-int
-NsfErrBadVal(Tcl_Interp *interp, char *context, char *expected, CONST char *value) {
-  Tcl_ResetResult(interp);
-  Tcl_AppendResult(interp, context, ": expected ", expected, " but got '", 
-		   value, "'", (char *) NULL);
-  return TCL_ERROR;
-}
-
 extern int
-NsfObjErrType(Tcl_Interp *interp, Tcl_Obj *value, CONST char *type, Nsf_Param CONST *pPtr) {
+NsfObjErrType(Tcl_Interp *interp, 
+	      CONST char *context, 
+	      Tcl_Obj *value, 
+	      CONST char *type, 
+	      Nsf_Param CONST *pPtr) 
+{
   NsfParam *paramPtr = (NsfParam *)pPtr;
   int named = (paramPtr && (paramPtr->flags & NSF_ARG_UNNAMED) == 0);
-  int returnValue = !named && (paramPtr->flags & NSF_ARG_IS_RETURNVALUE);
+  int returnValue = !named && paramPtr && (paramPtr->flags & NSF_ARG_IS_RETURNVALUE);
 
   /*fprintf(stderr, "NsfObjErrType param %p named %d\n", paramPtr, named);*/
 
   Tcl_ResetResult(interp);
+  if (context) {
+    Tcl_AppendResult(interp, context, ":",  (char *) NULL);
+  }
   Tcl_AppendResult(interp,"expected ", type, " but got \"",  ObjStr(value), "\"", (char *) NULL);
   if (named) {
     Tcl_AppendResult(interp," for parameter \"", paramPtr->name, "\"", (char *) NULL);