function popup(URLStr , width, height , scrollbars )

{
  var popUpWin=0;
  
  if(popUpWin)

  {

    if(!popUpWin.closed) popUpWin.close();

  }

  popUpWin = open(URLStr, 'popUpWin', 'toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars='+scrollbars+',resizable=no,copyhistory=yes,width='+width+',height='+height+'');

}