JavaScript使用setTimeout实现实时时钟显示

<!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>
 <meta http-equiv="content-type" content="text/html;charset=gb2312" />
 <title>JS小测试</title>
 </head>
 <body>
  <style type="text/css">
   #time
   {
    background-color:#eee;
   }
  </style>
  <script type="text/javascript">
   function showtime()
   {
    var myDate = new Date();
    document.getElementById("time").innerHTML = myDate.getHours()
 + "时" + myDate.getMinutes() + "分"
 + myDate.getSeconds() + "秒" ;
    setTimeout("showtime()",1000);
    }
</script>
  <div id="time">
   <script type="text/javascript">showtime();</script>
  </div>
 </body>
</html>