标签：style blog io ar color os sp java on
<!doctype html> <html> <style> body{ margin:0; padding:0; } #top{ background:#000; width:400px; height:30px; } .a{ position:fixed; top:0; left:0; } </style> <body> <div style="height:300px;width:100%;background:#ccc;"> </div> <div id="top"> </div> <div style="height:1900px;"> </div> <script> window.onscroll=function(){ var t = document.documentElement.scrollTop || document.body.scrollTop; var Otop = document.getElementById(‘top‘); if(t > 300){ var A = Otop.offsetHeight+Otop.offsetTop; Otop.style.position=‘fixed‘; Otop.style.left=‘0‘; Otop.style.top=‘0‘; }else{ Otop.style.position=‘‘; } } </script> </body> </html>
标签：style blog io ar color os sp java on
原文地址：http://www.cnblogs.com/xinlinux/p/4116673.html
