Math.random()后的延迟问题...

随机数重复了^_^<script language="javascript">
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// JavaScript Document
window.onload=initLink;var adImages=new Array("images/1.jpg","images/2.jpg","images/3.jpg");
var adLinks=new Array("google.com","baidu.com","gougou.com");
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var ch=0
function nextRotate(){
    var adNum=Math.floor((Math.random()*adImages.length));
    var img=document.getElementById("img2");
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    ch++
    document.getElementById("ttt").innerHTML=ch+":"+adNum
}
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    return false;
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<a href="texthtml.html"><img src="img2.jpg" alt="img2" id="img2"/></a>
<br>
<span id=ttt></span>
random()--伪随机，有相邻重复