<!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>
<title>Untitled Page</title>
<script type="text/javascript"> window.onload =function() {
var i = 4;
setInterval(function(){
if(i == 0) {
location.href = "http://www.baidu.com/";
}
document.getElementById("test").innerHTML = i--; },1000);
};
</script>
</head>
<body> <span id="test">5</span>秒后自动跳转
</body>
</html>