function sheild(){
	$.blockUI({ message:null});
}

function unsheild(){
	setTimeout($.unblockUI, 1000); 
}

function showNotices(url){
	$.blockUI({ message:null});
	alert(123213);
	window.open (url, '课程通知', 'height=100, width=400, top=0, left=0, toolbar=no, menubar=no, scrollbars=no, resizable=no,location=n o, status=no');
}