var popUpWin=0;
function sh_popup(URLStr,widthw,heightw)
{
  var width=(widthw>0) ? widthw:693;
  var height=(heightw>0) ? heightw:458;
  var left = parseInt((screen.availWidth/2) - (width/2));
  var top = parseInt((screen.availHeight/2) - (height/2));

  if(popUpWin)
  {
    if(!popUpWin.closed) popUpWin.close();
  }
  popUpWin = open(URLStr+'?popup', 'popUpWin', 'toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=yes,copyhistory=yes,width='+width+',height='+height+',left='+left+', top='+top+',screenX='+left+',screenY='+top+'');
}