/*增加一秒换一个的功能/运用定时器的用法。
<html>
<head>
<meta charset="utf-8">
<style type="text/css">
body,div,ul,li,img{
margin: 0px;
padding: 0px;
}
#menu{
width: 496px;
margin: auto;
}
#head{
border: 1px solid blue;
}
#head img{
width: 100%;
height: 300px;
}
#footer li{
list-style-type: none;
float: left;
border: 1px solid red;
width: 60px;
text-align: center;
padding: 5px 0px;
}
</style>
</head>
<body>
<div id="menu">
<div id="head">
<img src="img/1.jpg">
</div>
<div id="footer">
<ul>
<li onmouseover="showPic(1)">1</li>
<li onmouseover="showPic(2)">2</li>
<li onmouseover="showPic(3)">3</li>
<li onmouseover="showPic(4)">4</li>
<li onmouseover="showPic(5)">5</li>
<li onmouseover="showPic(6)">6</li>
<li onmouseover="showPic(7)">7</li>
<li onmouseover="showPic(8)">8</li>
</ul>
</div>
</div>
<script type="text/javascript">
var img = document.getElementsByTagName(‘img‘)[0];
var li = document.getElementsByTagName(‘li‘);
function showPic(num){
img.src = ‘img/‘+num+‘.jpg‘;
}
//图片轮播
var count =1;
function change(){
img.src = ‘img/‘+count+‘.jpg‘;
for(var i = 0; i < 8; i++){
li[i].style.background=‘‘;
}
li[count-1].style.background=‘blue‘;
count++;
if(count==9){
count = 1;
}
}
//定义个定时器
var timer = setInterval("change()",1000);
//鼠标移入图片上，停止播放
img.onmouseover = function(){
clearInterval(timer);
}
//鼠标离开，继续播放
img.onmouseout = function(){
timer = setInterval("change()", 1000);
}
</script>
</body>
</html>
原文：http://www.cnblogs.com/gjpup-00one/p/5052701.html