jquery 定时器

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE>Jquery实现页面定时跳转</TITLE>
<script language="javascript" type="text/javascript" src="jquery-1.4.2.min.js"></script>
<script language="javascript">
$(document).ready(function() {
function jump(count) {
window.setTimeout(function(){
count--;
if(count > 0) {
$('#last').attr('innerHTML', count);
jump(count);
} else {
location.href="http://www.baidu.com";
}
}, 1000);
}
jump(5);
});
</script>
</HEAD>
<BODY>
<span id="last">5</span>秒后将跳转到百度首页！</div>
</BODY>
</HTML>