function popUp(url,w,h)
	{
	var width = (w) ? w : 600;
	var height = (h) ? h : 550;
	var left = (window.screen.availWidth - width) /2;
	var top = (window.screen.availHeight - height) /2;
	window.open(url,'Popup','toolbar=no,status=no,menubar=no,scrollbars=no,resizable=yes,width='+width+',height='+height+',left='+left+',screenX='+left+',top='+top+',screenY='+top);
	}