自动伸缩广告代码，加载完毕后动态显示然后停顿n秒后动态收缩。
<html>
<head>
<title>test</title>
<script type="text/javascript">
var intervalId = null;
function slideAd(id,nStayTime,sState,nMaxHth,nMinHth)
{
this.stayTime=nStayTime*1000 || 3000;
this.maxHeigth=nMaxHth || 97;
this.minHeigth=nMinHth || 2.5;
this.state=sState || "down" ;
var obj = document.getElementById(id);
if(intervalId != null)
{
window.clearInterval(intervalId);
}