404.html

<!DOCTYPE HTML>
<html>
<head>
  <meta http-equiv="content-type" content="text/html;charset=utf-8;"/>
  <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1" />
  <meta name="robots" content="all" />
  <meta name="robots" content="index,follow"/>
</head>
<body>

<script type="text/javascript" src="http://www.qq.com/404/search_children.js"
        charset="utf-8" homePageUrl="your site url "
        homePageName="回到我的主页">
</script>

</body>
</html>