请问大神们 我的怎么不能运行啊
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<meta charset="UTF-8">
<title>Document</title>
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<body>
<h3>操作成功</h3>
<span><span id="miao">5</span>秒后回到主页</span><a href="javascript:sit();">返回</a>
<script>
var i=5;
function rec(){
document.getElementById("miao").innerHTML=i;
i=i-1;
if(i==1){
window.location.href="
}
}
timer=setInterval(rec(),1000);
function sit()
{history.go(-1);}
</script>
</body>
</html>
