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