JavaScript仿Windows关机效果

JavaScript仿Windows关机效果(5)             else OS = "an unknown operating system";
       }
}

function checkIt(string) {
        place = detect.indexOf(string) + 1;
        thestring = string;
        return place;
}
下面看一下网页加载时需要添加的方法。有关网页加载和初始化方法代码如下：
//网页加载调用initialize和getBrowserInfo方法
Event.observe(window, 'load', initialize, false);
Event.observe(window, 'load', getBrowserInfo, false);
//未加载时清空缓存
Event.observe(window, 'unload', Event.unloadCache, false);
//初始化方法
function initialize(){
        //调用该方法为该页添加覆盖层和高亮显示层
        addLightboxMarkup();
        //为每个可高亮显示的元素创建lightbox对象
        lbox = document.getElementsByClassName('lbOn');
        for(i = 0; i < lbox.length; i++) {
                    valid = new lightbox(lbox[i]);
        }
}

// 使用Dom方法创建覆盖层和高亮层
function addLightboxMarkup() {
        bod = document.getElementsByTagName('body')[0];
        overlay = document.createElement('div');
        overlay.id = 'overlay';
        lb = document.createElement('div');
        lb.id = 'lightbox';
        lb.className = 'loading';
        lb.innerHTML = '<div id="lbLoadMessage">' +
                                           '<p>Loading</p>' +