it's pseudo code, length(), findPos() and add() are imaginary functions that do what they mean. findPos returns the position of the argument in the list, if found, if not found it return FALSE. for(i=0, l=fromlist.length(); i<l; i++) { if ( ! tolist.findPos(fromlist[i]) ) { tolist.add(fromlist[i]); } } Cordialement, Damien COLA http://www.VarMalin.com