pWin = null;

function popupWin(url,width,height)
{
   if (width == null) {width = 350}
   if (height == null) {height = 355}

   if (pWin != null && !pWin.closed)
   {
      pWin.close(); pWin == null;
   }
   pWin = window.open(url,"popupWin","directories=no,location=no,menubar=no,resizable=no,scrollbars=no,status=no,toolbar=no,top=130,left=140,width=" + width + ",height=" + height);
}