/*
 * yuga.js 0.7.1 - 優雅なWeb制作のためのJS
 *
 * Copyright (c) 2009 Kyosuke Nakamura (kyosuke.jp)
 * Licensed under the MIT License:
 * http://www.opensource.org/licenses/mit-license.php
 *
 * Since:     2006-10-30
 * Modified:  2009-01-27
 *
 * jQuery 1.3.1
 * ThickBox 3.1
 */

/*
 * [使用方法] XHTMLのhead要素内で次のように読み込みます。
 
<link rel="stylesheet" href="css/thickbox.css" type="text/css" media="screen" />
<script type="text/javascript" src="js/jquery.js"></script>
<script type="text/javascript" src="js/thickbox.js"></script>
<script type="text/javascript" src="js/yuga.js" charset="utf-8"></script>

 */
function backToTop() {
var x1 = x2 = x3 = 0;
var y1 = y2 = y3 = 0;
if (document.documentElement) {
x1 = document.documentElement.scrollLeft || 0;
y1 = document.documentElement.scrollTop || 0;
}
if (document.body) {
x2 = document.body.scrollLeft || 0;
y2 = document.body.scrollTop || 0;
}
x3 = window.scrollX || 0;
y3 = window.scrollY || 0;
var x = Math.max(x1, Math.max(x2, x3));
var y = Math.max(y1, Math.max(y2, y3));
window.scrollTo(Math.floor(x / 2), Math.floor(y / 2));
if (x > 0 || y > 0) {
window.setTimeout("backToTop()", 25);
}
}