function CreatePopupWindow(windowname, url, width, height)
{
    if (! window.focus)
    return true;
   var href, left, top; 
  left = (screen.width - width) / 2
  top = (screen.height - height) / 2
  if (typeof(url) == 'string')
     href=url;
  else
     href=url.href;
  window.open(url, windowname, 'width='+width+',left='+left+',top='+top+',height='+height+',resizable=yes,scrollbars=yes,location=no,menubar=no,status=no,toolbar=no');
  
}