1 <!DOCTYPE HTML>
2 <html>
3 <head>
4 <meta charset="utf-8" />
5 <title>Div滚动到头以后置顶</title>
6 </head>
7 <body style="height:2000px;">
8 <div style="height: 200px"></div>
9 <div id="nav_keleyi_com" style="position:relative;top:0;background:#00f;width:100px; height:100px">
10 Test Div
11 </div>
12 </div>
13 <script type="text/javascript" >
14 function menuFixed(id){
15 var obj = document.getElementById(id);
16 var _getHeight = obj.offsetTop;
17
18 window.onscroll = function(){
19 changePos(id,_getHeight);
20 }
21 }
22 function changePos(id,height){
23 var obj = document.getElementById(id);
24 var scrollTop = document.documentElement.scrollTop || document.body.scrollTop;
25 if(scrollTop < height){
26 obj.style.position = 'relative';
27 }else{
28 obj.style.position = 'fixed';
29 }
30 }
31 </script>
32 <script type="text/javascript">
33 window.onload = function(){
34 menuFixed('nav_keleyi_com');
35 }
36 </script>
37 </body>
38 </html>