转自 http://www.codefans.net/jscss/code/2907.shtml
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title>图片提示</title>
<script src="/ajaxjs/jquery1.3.2.js" type="text/javascript"></script>
<style type="text/css">
body{
margin:0;
padding:40px;
background:#fff;
font:80% Arial, Helvetica, sans-serif;
color:#555;
line-height:180%;
}
img{border:none;}
ul,li{
margin:0;
padding:0;
}
li{
list-style:none;
float:left;
display:inline;
margin-right:10px;
border:1px solid #AAAAAA;
}
/* tooltip */
#tooltip{
position:absolute;
border:1px solid #ccc;
background:#333;
padding:2px;
display:none;
color:#fff;
}
</style>
<script type="text/javascript">
//<![CDATA[
$(function(){
var x =10;
var y =20;
$("a.tooltip").mouseover(function(e){
this.myTitle =this.title;
this.title ="";
var imgTitle =this.myTitle?"<br/>"+this.myTitle : "";
var tooltip ="<div id='tooltip'><img src='"+this.href +"' alt='产品预览图'/>"+imgTitle+"<\/div>"; //创建 div 元素
$("body").append(tooltip); //把它追加到文档中
$("#tooltip")
.css({
"top": (e.pageY+y) +"px",
"left": (e.pageX+x) +"px"
}).show("fast"); //设置x坐标和y坐标，并且显示
}).mouseout(function(){
this.title =this.myTitle;
$("#tooltip").remove(); //移除
}).mousemove(function(e){
$("#tooltip")
.css({
"top": (e.pageY+y) +"px",
"left": (e.pageX+x) +"px"
});
});
})
//]]>
</script>
</head>
<body>
<h3>有效果：</h3>
<ul>
<li><a href="/jscss/demoimg/wall1.jpg" class="tooltip" title="风光 iPod"><img src="/jscss/demoimg/wall_s1.jpg" alt="风光 iPod"/></a></li>
</ul>
<br/><br/><br/><br/>
<br/><br/><br/><br/>
<h3>无效果：</h3>
<ul>
<li><a href="/jscss/demoimg/wall1.jpg" title="风光 iPod"><img src="/jscss/demoimg/wall_s1.jpg" alt="风光 iPod"/></a></li>
</ul>
</body>
</html>