javascript正则表达式显示千分位货币

js 代码

<script language="JavaScript">
n="1279834847944074100465236.33"
re=/(\d{1,3})(?=(\d{3})+(?:$|\.))/g
n1=n.replace(re,"$1,")
alert(n+"\r\n"+n1)
document.write(n+"\r\n"+n1);
</script>