function openpopup(url,w,h)
  {
  	var winl = (screen.width - w) / 2;
  	var wint = (screen.height - h) / 2;
  	window.open(url, '_blank', 'menubar=0,location=0,scrollbars=no,resizable=0,status=0,width='+w+',height='+h+',top='+wint+',left='+winl); 
  }