var popupwin = null;
  function popup(loc,ww,hh) 
   {
    var mywidth = (ww + 0);
    var myheight = (hh + 0);
    var myspecs = "'menubar=0,status=1,resizable=1,location=0,titlebar=1,toolbar=1,scrollbars=1,width=" + mywidth + ",height=" + myheight + "'";
      if (popupwin == null || popupwin.closed) 
			{
            popupwin = window.open (loc, 'popupwin', myspecs);
           }
		 else 
		   {
            popupwin.focus();
            popupwin.location.href = loc;
          }
    }