两种广告轮换代码

<script>
var i=1;
var cnt = 3; //修改这里，增加广告数目
var tmpobj = setInterval("addtime()",1000); //这里调整你的轮换时间
function $(name){
    return document.getElementById(name);
}
function showAds(currentId){
    for(var i=1; i<=cnt;i++)$("indexsrh"+i).style.display='none';
    $("indexsrh"+currentId).style.display='block';
}
function addtime()
{
if(i>3)i=1;
showAds(i);
i++;
}
</script>
<div id="indexsrh1" style="display:block"><img src="http://www.55.la/banner_more_pic/admin_view_pic/1121.gif" /></div>
<div id="indexsrh2" style="display:none "><img src="http://image2.55.la/anonymous/banner/2008/10/06/18/2845885.gif" /></div>
<div id="indexsrh3" style="display:none "><img src="http://www.baidu.com/img/baidu_logo_rw_0810_wiley.gif" /></div>

<div id="adpic">
                        <img src="1.gif" style="display:none">
                        <img src=".2.gif" style="display:none">
        <img src="3.gif" style="display:none">
                        <img src="4.gif" style="display:none">
        <img src="5.gif" style="display:none">
                        <img src="6.gif" style="display:none">
                      
                   </div>
                   <script language="JavaScript" type="text/javascript">
                   <!--
                    function runad()
                        {
                         var ads=document.getElementById("adpic").getElementsByTagName("img")
                         for(var i=0,adsc=ads.length;i<adsc;i++)
                         {
                          ads[i].style.display='none';
                         }
                         ads[parseInt(Math.random()*ads.length)].style.display='';
                        }
                        function run()
                        {
                         //广告执行函数
                          runad();
                        }
                        window.onload=run
                   //-->
                   </script>