在js中实现页面定时跳转我们要使用setInterval或setTimeOut函数，还可以使用页面的meta实现。
例1：
<script type="text/javascript" language="JavaScript">
var startTime = new Date();
var endTime=startTime.getTime()+10*60*1000;
var g_blinkswitch = 0;
var g_blinktitle = document.title;
function getRemainTime(){
var nowTime = new Date();
var nMS =endTime - nowTime.getTime();
var nM=Math.floor(nMS/(1000*60)) % 60;
var nS=Math.floor(nMS/1000) % 60;
if(nM==0&&nS==0&&nMS<1000) //当倒计时结束
{
window.focus();
setInterval("blinkNewMsg()", 1000);
window.location.reload();
}
if(nS < 10) nS = "0" + nS;
if(nMS >= 0){
document.getElementById("remainTime").innerHTML= nM + "分" + nS + "秒";
setTimeout("getRemainTime()",1000);
}
}
function blinkNewMsg()
{
document.title = g_blinkswitch % 2==0 ? "【 】 - " + g_blinktitle : "【新消息】 - " +
g_blinktitle;
g_blinkswitch++;
}
window.onload=getRemainTime;
</script>
<strong id="remainTime">10分00秒</strong>
例2
倒计时跳转页面
<title>JS倒计时网页自动跳转代码</title>
<script language="JavaScript" type="text/javascript">
function delayURL(url) {
var delay = document.getElementById("time").innerHTML;
if(delay > 0) {
delay--;
document.getElementById("time").innerHTML = delay;
} else {
window.top.location.href = url;
}
setTimeout("delayURL('" + url + "')", 1000);
}
</script>
<span id="time" style="background: #00BFFF">3</span>秒钟后自动跳转，如果不跳转，请点击下面的链接<a href="http://www.jbxue.com">脚本学堂</a>
<script type="text/javascript">
delayURL("http://www.jbxue.com");
</script>
例3 防刷新的倒计时代码
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title> www.jbxue.com--倒计时页面</title>
</head>
<body>
<SCRIPT LANGUAGE="JavaScript">
<!--
var maxtime;
if(window.name==''){
maxtime = 1*60;
}else{
maxtime = window.name;
}
function CountDown(){
if(maxtime>=0){
minutes = Math.floor(maxtime/60);
seconds = Math.floor(maxtime%60);
msg = "距离考试结束还有"+minutes+"分"+seconds+"秒";
document.all["timer"].innerHTML = msg;
if(maxtime == 5*60) alert('注意，还有5分钟!');
--maxtime;
window.name = maxtime;
}
else{
clearInterval(timer);
alert("考试时间到，结束!");
}
}
timer = setInterval("CountDown()",1000);
//-->
</SCRIPT>
<div id="timer" style="color:red"></div>
</body>
</html>