function showDiv(obj) {
      document.getElementById(obj).style.display = 'block';
  }

  function hideDiv(obj) {
      document.getElementById(obj).style.display = 'none';
  }

  function show_popup(URL, wname, wwidth, wheight) {

	var wleft = (screen.width-wwidth)/2;
	var wtop = (screen.height-wheight)/2;
	window.open(URL, wname, 
		'toolbar=no,location=no,titlebar=yes,status=yes,menubar=no,'+
		'resizable=no,copyhistory=no,scrollbars=yes,'+
		'width='+wwidth+',height='+wheight+',top='+wtop+',left='+wleft);
  }


  function image_popup(URL, wwidth, wheight) {

	return show_popup(URL, '_blank', wwidth, wheight);
 
  }