Demo:


Cách làm:
Chèn toàn bộ code sau vào footer_end.

Code:

<a href="#top" id="top_link" onmouseover="animateTopLink()" onmouseout="animateTopLink()" style="right: -100px; ">Lên đầu trang</a><style>#top_link {background: url(http://hot.dinhcao.vn/wp-content/themes/FolioGridPro/images/arrow.png) no-repeat 9px 9px #444;color: white;}#top_link {text-shadow: none;font-size: 1.1em;padding: 9px 20px 9px 31px;margin: 0 10px 0 0;position: fixed;right: -100px;top: 90%;text-decoration: none;width: 69px;-moz-border-radius: 5px;-webkit-border-radius: 5px;}#top_link:hover            { background:url(http://hot.dinhcao.vn/wp-content/themes/FolioGridPro/images/arrow.png) no-repeat 9px 9px #fe0000; }</style>
<script type="text/javascript" src="http://hot.dinhcao.vn/wp-content/themes/FolioGridPro/js/foliogrid.js"></script>

Good luck!