JavaScript仿Windows关机效果

JavaScript仿Windows关机效果(3)        BACKGROUND: #fdfce9;
       LEFT: 50%;
       MARGIN: -220px 0px 0px -250px;
       BORDER-LEFT: #fff 1px solid;
       WIDTH: 500px;
       BORDER-BOTTOM: #fff 1px solid;
       POSITION: absolute;
       TOP: 50%;
       HEIGHT: 400px;
       TEXT-ALIGN: left
}
UNKNOWN {
     POSITION: fixed
}
#overlay {
      DISPLAY: none;
      Z-INDEX: 5000; FILTER: alpha(opacity=80);
      LEFT: 0px;
      WIDTH: 100%;
      POSITION: absolute;
      TOP: 0px;
      HEIGHT: 100%;
      BACKGROUND-COLOR: #000; moz-opacity: 0.8; opacity: .80
}
UNKNOWN {
    POSITION: fixed
}
.done#lightbox #lbLoadMessage {
      DISPLAY: none
}
.done#lightbox #lbContent {
      DISPLAY: block
}
.loading#lightbox #lbContent {
      DISPLAY: none
}
.loading#lightbox #lbLoadMessage {
       DISPLAY: block
}
.done#lightbox IMG {
      WIDTH: 100%; HEIGHT: 100%
}
客户端脚本
由于浏览器对图层的支持不同，所以首先要确定客户端浏览器的类型。以下代码可用于判断客户端的浏览器和操作系统。
var detect = navigator.userAgent.toLowerCase();
var OS,browser,version,total,thestring;

function getBrowserInfo() {
       if (checkIt('konqueror')) {