<!DOCTYPE html>
<html>
<head>
<title>浏览器对象</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312"/>
</head>
<body>
<h1>操作成功</h1>
<span id="seconds">5</span><span>秒返回主页</span><a href="javascript:back()">返回</a>
<script type="text/javascript">
var sec = document.getElementById("seconds");
var num=5;
function count(){
num--;
sec.innerHTML=num;
if(num==1){
window.location.href="http://www.imooc.com";
}
}
var interval=setInterval("count()",1000);
function back(){
window.history.back();
}
</script>
</body>
</html>
返回上一次访问的记录呀，你点击没有触发是因为没有记录。