onbeforeunload第一次不起作用。但是当我按ctrl + shift + t时。它可以正常工作。谁能指导
我尝试了以下代码
<html>
<head>
</head>
<body>
<script type="text/javascript">
window.onbeforeunload = function(evt) {
var message = 'Are you sure you want to leave?';
return message;
}
</script>
<div>Hi</div>
</body>
</html>