var h_handle = null;

 function prompt_with_popup(v_url,v_width,v_height) {
  if (window.screen) {
   var side_margin_pct = v_width;
   var top_bot_margin_pct = v_height;
   var side_margin_px = screen.availWidth * side_margin_pct;
   var top_bot_margin_px = screen.availHeight * top_bot_margin_pct;
   var ah = screen.availHeight - (top_bot_margin_px * 2);
   var aw = screen.availWidth  - (side_margin_px * 2);
   var str= "resizable,dependent,scrollbars,width=" + aw + ",height=" + ah;
   str += ",left=" + side_margin_px + ",screenX=" + side_margin_px;
   str += ",top=" + top_bot_margin_px + ",screenY=" + top_bot_margin_px;
   }
   h_handle = open(v_url,"search",str);
   h_handle.focus();
 }

 function refocus_child()
 {
  if (h_handle && !h_handle.closed) {
   h_handle.focus();
  }
 }