JS实时监听浏览器联网状态

兼容浏览器写法

var EventUtil = {
    addHandler: function (element, type, handler) {
        if(element.addEventListener) {
            element.addEventListener(type, handler, false);
        }else if (element.attachEvent) {
            element.attachEvent("on" + type, handler);
        }else {
            element["on" + type] = handler;
        }
    }
};
EventUtil.addHandler(window, "online", function () {
    document.write("连上网了！");
});
EventUtil.addHandler(window, "offline", function () {
    document.write("网络不给力，请检查网络设置!");
});