最简单js控制10秒后页面自动跳转

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>404 Not Found</title>
<style type="text/css">

</style>
<script type="text/javascript">
// -------- 返回指定到url
function countDown(secs,surl)
{
var jumpTo = document.getElementById('jumpTo');
jumpTo.innerHTML=secs;
if(--secs>0)
{
    setTimeout("countDown("+secs+",'"+surl+"')",1000);
}
else
{
     location.href=surl;
}
}

// --------- 返回上一页
function countDown(secs)
{
var jumpTo = document.getElementById('jumpTo');
jumpTo.innerHTML=secs;
if(--secs>0)
{
    setTimeout("countDown("+secs+")",1000);
}
else
{
    history.go(-1);
}
}
</script>
</head>
<body onload="begintimer()">
<div align="center">
<h2><span class="t">404，抱歉，您访问的页面不存在！</span></h2>
<table border="0" cellpadding="8" cellspacing="0" width="50%">
    <tbody>
      <tr>
        <td class="c">
          <br/>
        The requested URL was not found on this server.
        <br/>
        <br/>
        <span id="jumpTo">10</span>秒后，页面将返回上一页！
    <script type="text/javascript">countDown(10);</script>
        </td>
      </tr>
    </tbody>
</table>
</div>
</body>
</html>