<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>广告自动关闭</title>
</head>
<style>
.tip{
position: fixed;
top: 100px;
left: 400px;
display: block;
width: 400px;
height: 200px;
border-style: dotted;
border-width: thin;
border-color: darkgreen;
background: #f0c;
z-index: 100;
} </style>
<script type="text/javascript" src="js/base.js"></script>
<script>
/*
window.onload = function(){
var timer = setInterval(function(){
var _span = document.getElementsByTagName("span")[0];
_span.innerHTML -= 1; if(_span.innerHTML == 0){
clearInterval(timer);
document.getElementById("ad").style.display = "none";
}
},1000);
}
*/ window.onload = function(){
var num = 5;
var oDiv = document.getElementById("ad");
var t = setInterval(function(){
countDown();
if(num == 0) {
clearInterval(t);
oDiv.style.display = "none";
}
},1000); function countDown(){
oDiv.children[0].innerHTML -= 1;
num--;
}
}
</script>
<body>
<div id="ad" class="tip">
我是一条广告，谢谢！
<span style="color:yellow; font-weight:bold;">5</span>秒钟后自动关闭
</div>
</body>
</html>