js 3秒后跳转页面的实现代码

$(function(){
Load(URL);
})
var secs = 3; //倒计时的秒数
var URL = "<?= url('/infomation/businessapply')?>" ;
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; }
}

<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="http://www.baidu.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 = "http://www.baidu.com";
}
}
</script>