js阻止浏览器关闭

<script lang="typescript/js">

window.isCloseHint = true;

//初始化关闭

window.addEventListener("beforeunload", function(e) {

    if (window.isCloseHint) {

        var confirmationMessage = "要记得保存！你确定要离开我吗？";

        (e || window.event).returnValue = confirmationMessage; // 兼容 Gecko + IE

        return confirmationMessage; // 兼容 Gecko + Webkit, Safari, Chrome

    }

});

</script>