--- branches/new_design/OOPSE-4/src/UseTheForce/ForceField.cpp	2004/11/12 17:40:03	1735
+++ branches/new_design/OOPSE-4/src/UseTheForce/ForceField.cpp	2004/11/15 23:00:32	1740
@@ -117,4 +117,36 @@ double ForceField::getRcutFromAtomType(AtomType* at) {
     
 }
 
+
+ifstrstream* ForceField::openForceFiledFile(const std::string& filename) {
+    std::string forceFieldFilename(filename);
+    ifstrstream* ffStream = new ifstrstream();
+    
+    //try to open the force filed file in current directory first    
+    ffStream.open(forceFieldFilename.c_str());
+    if(!ffStream.is_open()){
+
+        forceFieldFilename = ffPath_ + "/" + forceFieldFilename;
+        ffStream.open( forceFieldFilename.c_str() );
+
+        //if current directory does not contain the force field file,
+        //try to open it in the path        
+        if(!ffStream.is_open()){
+
+            sprintf( painCave.errMsg,
+               "Error opening the force field parameter file:\n"
+               "\t%s\n"
+               "\tHave you tried setting the FORCE_PARAM_PATH environment "
+               "variable?\n",
+               forceFieldFilename.c_str() );
+            painCave.severity = OOPSE_ERROR;
+            painCave.isFatal = 1;
+            simError();
+        }
+    }  
+
+    return ffStream;
+
+}
+
 } //end namespace oopse