<!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>导航固定</title>
<script
src="/ajaxjs/jquery1.3.2.js"language="javascript"
type="text/javascript"></script>
<script>
$(function(){
$(window).scroll(function() {
//$("body").css({"background-position":"center
"+$(window).scrollTop()+""});
if($(window).scrollTop()>=250){
$(".nav").addClass("fixedNav");
}else{
$(".nav").removeClass("fixedNav");
}
});//www.111cn.net
});
</script>
<style>
*{
margin:0px;
padding:0px;
}
div.nav{
background:#000000;
height:57px;
line-height:57px;
color:#ffffff;
text-align:center;
font-family:"微软雅黑",
"黑体";
font-size:30px;
}
div.fixedNav{
position:fixed;
top:0px;
left:0px;
width:100%;
z-index:100000;
_position:absolute;
_top:expression(eval(document.documentElement.scrollTop));
}
</style>
</head>
<body>
<div class="header"
style="background:#CCCC00;height:250px;"></div>
<div
class="nav">
<p>导航固定</p>
</div>
<div
class="content" style="background:#0099FF;
height:2000px;"></div>
</body>
</html>
更多详细内容请查看：http://www.111cn.net/wy/jquery/57861.htm
原文：http://www.cnblogs.com/alibai/p/3548974.html