function PopWindow(page)
{
  w=600;
  h=500;
  l=(screen.width-w)/2;
  t=(screen.height-h)/2;
  win=window.open(page,'','menubar=no,scrollbars=yes,toolbar=no,location=no,directories=no,resizable=yes,width='+w+',height='+h+',left='+l+',top='+t);
  return false;
}