适合iwms使用的对联广告脚本，兼容ie/firefox/opera，实现页面上下滚动时广告浮动跟随。
以下为演示代码，关键部分标记为蓝色，你可以复制后调整使用。
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="gb2312">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>对联广告效果</title>
</head>
<body bgcolor="#66CCFF">
<script language="javascript">
<!--
//===================
// 对联广告效果脚本
// by 木鸟 2007.11.14
// www.iwms.net
// 转载及使用请保留本信息
//===================
var m_layer1,m_layer2;
function initMove() {
m_layer1=document.getElementById("AdLayer1");
m_layer2=document.getElementById("AdLayer2");
m_layer1.style.top = "-200px";
m_layer1.style.visibility = 'visible'
m_layer2.style.top = "-200px";
m_layer2.style.visibility = 'visible'
MoveLayers();
window.onscroll=MoveLayers;
}
function MoveLayers() {
var x = 5; // 左右边距
var y = 100; // 顶距
var st=document.documentElement.scrollTop;
var cw=document.documentElement.clientWidth;
var y = st + y;
m_layer1.style.top = y+"px";
m_layer1.style.left = x+"px";
m_layer2.style.top = y+"px";
m_layer2.style.left = cw-m_layer2.clientWidth-x+"px";
}
window.setTimeout("initMove()",600);
//-->
</script>
<div id='AdLayer1' style='position: absolute;visibility:hidden;z-index:1'><a href="http://www.iwms.net/buy"><img src='http://www.iwms.net/buy/pic/product_6.gif' border='0'></a></div>
<div id='AdLayer2' style='position:absolute;visibility:hidden;z-index:1'><a href="http://www.iwms.net/buy"><img src='http://www.iwms.net/buy/pic/product_8.gif' border='0'></a></div>
<div align="center" style="height:2000px">
<h3>对联效果</h3>
<br/><br/>
说明：该脚本由木鸟编写，适用于IE/Firefox/Opera。<br/><br/>
<a href="http://www.iwms.net/">www.iwms.net</a>
</div>
<h3> </h3>
<p> </p>
<p> </p>
</body>
</html>
这段代码放在什么位置，请教一下？