求助，请大家帮忙看看。。

骑着毛驴去探亲 2013-11-14 12:17:37

<!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>页面滚动效果</title>

<style type="text/css">

*{margin:0;padding:0;list-style-type:none;}

a,img{border:0;}

body{font:12px/180% Arial, Helvetica, sans-serif, "新宋体";background:#B6CDFC;}

#main{width:800px;min-height:600px;margin:30px auto 0 auto;background:#fff;-moz-border-radius:12px;-khtml-border-radius: 12px;-webkit-border-radius:12px;border-radius:12px;}

/* nav */

.nav{width:50px;position:fixed;top:5%;z-index:1999;background:#f0f0f0;border:1px solid #ccc;margin:10% 0 0 0;

	-webkit-border-radius:6px;

	-moz-border-radius:6px;

	border-radius:6px;

	

	-webkit-box-shadow:0 5px 10px rgba(0, 0, 0, 0.2);

	-moz-box-shadow: 0 5px 10px rgba(0, 0, 0, 0.2);

	box-shadow:0 5px 10px rgba(0, 0, 0, 0.2);

}

*html,*html body{background-image:url(about:blank);background-attachment:fixed;}

*html .nav{position:absolute;top:expression(eval(document.documentElement.scrollTop));}

  

.nav li{height:50px; line-height:50px; border-bottom:1px solid #d3d3d3; background:url(img/icon.png) no-repeat; text-align:center; cursor:pointer}

.nav li:hover{background-color:#f9f9f9; text-decoration:none}

.nav li:last-child{border-bottom:none}

.nav li.cur{background-color:#ffc}

.nav li.pro{background-position:0 0}

.nav li.news{background-position:0 -55px}

.nav li.ser{background-position:0 -105px}

.nav li.con{background-position:0 -155px}

.nav li.job{background-position:0 -207px}

/* box */

.box{height:700px; margin: 0 10px}

.box h3{height:32px; line-height:32px; padding-left:20px; font-size:14px}

.box p{line-height:30px; margin:20px; text-align:center; font-size:28px}

.box p span{margin:10px}

#pro,#ser{background:url(img/bg.jpg)}

#news,#con{background:url(img/bg2.gif)}

</style>

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>

<script type="text/javascript" src="jquery.easing.min.js"></script>

<script type="text/javascript">

$(function(){



	var pro_top = $("#pro").offset().top;

	var news_top = $("#news").offset().top;

	var ser_top = $("#ser").offset().top;

	var con_top = $("#con").offset().top;

	var job_top = $("#job").offset().top;

	//alert(tops);

	$(window).scroll(function(){

		var scroH = $(this).scrollTop();

		if(scroH>=job_top){

			set_cur(".job");

		}else if(scroH>=con_top){

			set_cur(".con");

		}else if(scroH>=ser_top){

			set_cur(".ser");

		}else if(scroH>=news_top){

			set_cur(".news");

		}else if(scroH>=pro_top){

			set_cur(".pro");

		}



		var s = $(document).scrollTop();	

		if(s > t - 10){

			$('.leftFix').css('position','fixed');

			if(s + fh > mh){

				$('.leftFix').css('top',mh-s-fh+'px');	

			}				

		}else{

			$('.leftFix').css('position','');

		}



	});

	

	$(".nav li").click(function() {

		var el = $(this).attr('class');

		$('html, body').animate({

		 	scrollTop: $("#"+el).offset().top

			},{

         	easing: 'easeOutSine',

         	duration: 300,

         	complete:function(){

			}

	 	});

 	});

});



function set_cur(n){

	if($(".nav li").hasClass("cur")){

		$(".nav li").removeClass("cur");

	}

	$(".nav li"+n).addClass("cur");

}

</script>

</head>



<body>



<div style="height:300px;overflow:hidden;background:#ccc;"></div>

<div style="width:980px;margin:auto;">

<ul class="nav">

	<li class="pro"></li>

	<li class="news"></li>

	<li class="ser"></li>

	<li class="con"></li>

	<li class="job"></li>

</ul>



<div id="main">

	

	<div id="pro" class="box">

		<h3>产品展示</h3>

		

	</div>

	

	<div id="news" class="box">

		<h3>新闻中心</h3>

	</div>

	

	<div id="ser" class="box">

		<h3>服务支持</h3>

	</div>

	

	<div id="con" class="box">

		<h3>联系我们</h3>

	</div>

	

	<div id="job" class="box">

		<h3>人才招聘</h3>

	</div>

	

</div>

</div>

<div style="height:1000px;overflow:hidden;background:#ccc;"></div>

</body>

</html>