var is_open = false;
 
function open_window(theURL,winName,w,h) {
 var features = "width=" + w + ",height=" + h;
 if (is_open) {
  if (my_window.closed == true) {
   my_window = window.open(theURL,winName,features);
   my_window.resizeTo(w,h);
   }
  else {
   my_window.resizeTo(w,h);
   my_window.location = theURL;
   } 
  }
 else { 
  my_window = window.open(theURL,winName,features);
  my_window.resizeTo(w,h);
  is_open = true;
  }
 my_window.focus();
 }