var Pop = null;
function popdown() {
	if (Pop && !Pop.closed) Pop.close();
}
function popup(obj,w,h) {
	var url = (obj.getAttribute) ? obj.getAttribute('href') : obj.href;
	if (!url) return true;
	w = (w) ? w += 20 : 150;
	// 150px*150px is the default size h = (h) ? h += 25 : 150;
	var args = 'width='+w+',height='+h+',toolbar=no,location=no,directories=no,status =no,menubar=no,scrollbars=yes,resizable=yes,copyhistory=no';
	popdown();
	Pop = window.open(url,'',args);
	Pop.focus();
	return (Pop) ? false : true;
}
window.onunload = popdown;
//window.onfocus = popdown;