浮动层无法遮住object对象

有时候网页需要嵌入delphi等object对象，浮动定位层就无法浮在最上层了，解决办法：

var divWin = document.createElement("div");
    divWin.id = "ProgressBarDiv";
    divWin.style.cssText = "position:fixed; top:0; left:0; z-index:20000; width:300px; height:300px;filter:alpha(opacity=100);background-color:#000;display:block;";
    document.body.appendChild(divWin);
    var iframeWin = document.createElement("iframe");
    iframeWin.id = "ProgressBarIframe";
    iframeWin.style.cssText = "position:fixed;top:0;left:0;width:300px; height:300px;background-color:#000;filter:alpha(opacity=100);display:block;z-index:19999;";
    iframeWin.src ="javascript:false;";
    document.body.appendChild(iframeWin);