Javascript倒计时显示页面跳转

javaScript页面跳转的效果：

     <span id="time" style="background:red">5</span>秒钟后，页面会自动跳转，如果不跳转请单击下面的链接<a href="article.jsp">回到主页</a>
<script language="JavaScript1.2" type="text/javascript">

function delayURL(url) {
 var delay = document.getElementById("time").innerHTML;//拿到标签id=time的值
 if(delay > 0) {//如果delay大于0，就减1，然后对delay重新赋值
  delay--;
  document.getElementById("time").innerHTML = delay;
 } else {
  window.top.location.href = url ;
 }
    setTimeout("delayURL('" + url + "')", 1000);
}

</script>
<script type="text/javascript">
delayURL("article.jsp");
</script>