JavaScript–在標題列顯示時間

在標題列顯示時間：
<script language="JavaScript1.2">
<!--
var isnMonth = new Array("1月","2月","3月","4月","5月","6月","7月","8月","9月","10月","11月","12月");
var isnDay = new Array("星期日","星期一","星期二","星期三","星期四","星期五","星期六","星期日");
today = new Date() ;
Year=today.getYear();
Date=today.getDate();
if(document.all)
document.title="歡迎你，今天是: "+Year+"年"+isnMonth[today.getMonth()]+Date+"日"+isnDay[today.getDay()]
//-->
</script>