<html>
<head><title>JS测试</title>
<script type="text/javascript">
window.onbeforeunload = function(event){
var msg = \'\';
msg +=\'您确定要放弃此商品的购买？\n\';
msg += \'★多款产品任选，购买即享超低折扣。\';
return msg;
};
</script>
</head>
<body>
JS测试，关闭页面时候，弹出提示对话框！
</body>
</html>