var popUpWin=0;

function popUpWindow(URLStr, width, height)
{
  if(popUpWin)
  {
    if(!popUpWin.closed) popUpWin.close();
  }
  
  var left = (screen.width/2) - (width/2);
  var top = (screen.height/2) - (height/2);
  popUpWin = open(URLStr, 'popUpWin', 'toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=no,copyhistory=yes,width='+width+',height='+height+',left='+left+', top='+top+',screenX='+left+',screenY='+top+'');
}