javascript window close event confirm

當瀏覽器關閉的時會先呼叫，不會直接關閉。

window.onbeforeunload = function (e) {
    e = e || window.event;

    // For IE and Firefox prior to version 4
    if (e) {
        e.returnValue = 'Any string';
    }

    // For Safari
    return 'Any string';
};


 Here is a working jsFiddle