function backToTop(){
	var aTagList = document.getElementsByTagName('a');
	for (var i = 0; i < aTagList.length; i++) {
		if (aTagList[i].href.match(/#header-menu/i)) {
			aTagList[i].onclick = toPageTop;
		}
	}
}
var toTopMove = 15;
var toTopPosi;
function toPageTop() {
	var yPos = document.body.scrollTop || document.documentElement.scrollTop;
	mObj(yPos);
	return false;
}
function mObj(y, s) {
	if (s) toTopMove = s;
	toTopPosi = parseInt(y - y * 2 / toTopMove);
	scrollTo(0, toTopPosi);
	if (toTopPosi > 0) setTimeout('mObj(toTopPosi, toTopMove)', 1);
}
if (window.addEventListener) window.addEventListener('load', backToTop, false);
if (window.attachEvent) window.attachEvent('onload', backToTop);