diff --git a/tracy/tracy/src/t2elem.cc b/tracy/tracy/src/t2elem.cc
index a6ec5c6a6e3d2583ac2526503ec04f1edccd75d1..a28630b51593d85787c1a4be5b05ee71d34338a7 100644
--- a/tracy/tracy/src/t2elem.cc
+++ b/tracy/tracy/src/t2elem.cc
@@ -2893,11 +2893,26 @@ int GetnKid(const int Fnum1) {
  none
 
  Comments:
+ example:
+  long FORLIM = GetnKid(ElemIndex("CH")); // get number of CH
+  // search element position for Family CH
+  for(k=1;k<FORLIM;k++){
+  fprintf(stdout, "elem %d is at position %ld \n", k, Elem_GetPos(ElemIndex("CH"), k));
+  }
+
+  
+  21/12/2011  Jianfeng Zhang@ soleil
+  Add warning message: when call Elem_GetPos(), the kid index knum1 start from 1 !!!!!
 
  ****************************************************************************/
 long Elem_GetPos(const int Fnum1, const int Knum1) {
     long int loc;
-
+    
+    if(Knum1 < 1){
+    cout << "Elem_GetPos:  kid index of the family starts from 1 !!!" << endl;
+    cout << "Element: " << ElemFam[Fnum1 - 1].ElemF.PName << "with Fnum:  " <<Fnum1<<"  Knum: "<<Knum1<<endl;
+    exit_(1); 
+    }
     if (ElemFam[Fnum1 - 1].nKid != 0)
         loc = ElemFam[Fnum1 - 1].KidList[Knum1 - 1];
     else {