shown=''
function OpenF(url,w,h) 
 {
   var str="";
   str="scrollbars=no, status=no, high, width="+w+", height="+h;
   if( shown=='' || shown.closed) 
        shown=window.open(url,'OpenF', str);
   else 
     { 
        shown.close();
        shown=window.open(url,'OpenF', str);
     }
 }