窄告网中的广告实现方式，高手请进！！

窄告网的广告发布样式中有一种在右边以小图标形式展示，点击会出来一个大的广告。再点击又可以返回。在线展示网址：
http://www.prnews.cn/press_release/17843.htm
您也可以保存以下代码，看看效果。<html>
<head>
<title>商业电讯</title>
</head>
<body><SCRIPT>var tixa_nadInIframe=false; <!-- iframe flag -->var tixa_nadRowCount=1; <!--the row count of narrowad-->var tixa_nadColumnCount=4;<!--the column count of narrowad-->var tixa_nadHeight=85; <!--total height of narrowad-->var tixa_nadWidth=775; <!--total width of narrowad-->var tixa_nadBorderColor='9178E7'; <!--the color of the narrowad's border-->var tixa_nadBgColor='F0ECFF'; <!--the color of the narrowad's background-->var tixa_nadTitleColor='0000ff'; <!--the color of the ad's title-->var tixa_nadDescColor='000000'; <!--the color of the ad's description-->var tixa_adType='text'; <!--narrowad type-->
document.write('<scr'+'ipt src="http://210.192.125.51/proxy/sensetext_pr.jsp?wid=172&cid=32473&na=no"></sc'+'ript>');if(tixa_nadWidth<100 || tixa_nadHeight<70){
    tixa_nadWidth=680;
    tixa_nadHeight=85;
}
var narrowad_clientUrl = document.location.href;
if(narrowad_clientUrl.indexOf(".narrowad.com/")>0){
    document.location.href="http://www.narrowad.com";
}
var narrowad_inIframe = 0;
if(self!=top){
    narrowad_inIframe = 1;    
}
if (self!=top && window.tixa_nadInIframe && window.tixa_nadInIframe==true) 
    narrowad_clientUrl = document.referrer;
var narrowad_nadIsHeader = 1;
if(window.tixa_nadNoHeader && window.tixa_nadNoHeader==true){
    narrowad_nadIsHeader=0;
}var narrowad_nadDescRows=2;
if(window.tixa_nadDescRows || window.tixa_nadDescRows==0){
    narrowad_nadDescRows=tixa_nadDescRows;
}var mm_src = "http://union.narrowad.com/mm2/mmpub.jsp"
                        + "?def=1649867163"
                        + "&origin=narrowad"
                        + "&pc=21e46357d8fe"
                        + "&wid=172"
                        + "&cid=32473"
                        + "&userID="
                        + "&websiteType=2"
                        + "&crowdID=1"
                        + "&areaID=2"
                        + "&inIframe=" + narrowad_inIframe
                        + "&userUrl=" + encodeURIComponent(narrowad_clientUrl);var mm_link = "<scr" + "ipt src=\"" + mm_src + "\"></scri" + "pt>";
document.write(mm_link);
</SCRIPT></body>
</html>＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
请您保存此页面，看看效果，它右边的广告是怎么实现的。这个脚本应该很复杂。请高手赐教！！