scroll2Top 是个简单的自定义 jQuery 插件，用来滚动回到顶部。
#to_the_top { display: none; position: fixed; cursor: pointer; /* modify below css to your needs */ background: url('images/top.png') no-repeat left top; width: 60px; height: 60px; top: 240px; right: 50px; } 
项目主页：http://www.open-open.com/lib/view/home/1394799633290