js 3秒后跳转页面的实现代码

<script language="javascript">
var secs = 3; //倒计时的秒数
var URL ;
function Load(url){
URL = url;
for(var i=secs;i>=0;i--)
{
   window.setTimeout('doUpdate(' + i + ')', (secs-i) * 1000);
}
}
function doUpdate(num)
{
document.getElementById('ShowDiv').innerHTML = '将在'+num+'秒后自动跳转到主页' ;
if(num == 0) { window.location = URL; }
}
</script>

<p style="text-indent: 2em; margin-top: 30px;">
系统将在 <span id="time">5</span> 秒钟后自动跳转至新网址，如果未能跳转，<a href="//www.VeVB.COm" title="点击访问">请点击</a>。</p>
<script type="text/javascript">  
    delayURL();   
    function delayURL() {
        var delay = document.getElementById("time").innerHTML;
 var t = setTimeout("delayURL()", 1000);
        if (delay > 0) {
            delay--;
            document.getElementById("time").innerHTML = delay;
        } else {
     clearTimeout(t); 
            window.location.href = "//www.VeVB.COm";
        }       
    }
</script>