Js 页面在5秒钟后跳转,页面自动跳转

<div id="div1">5</div>
<script type="text/javascript">
    var   i=5
    function   changepage()
    {
        div1.innerHTML=i
        i=i-1
        if(i==1)
        {
            document.location="Admin_Index_Main.htm";
        }
        setTimeout("changepage()",1000)
    }
    changepage()
</script>