function ReturnToTop(pos,now) {
var x1 = x2 = x3 = 0;
var y1 = y2 = y3 = y4 = 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));
if (!pos) {
//ページトップへ
window.scrollTo(Math.floor(x / 1.25), Math.floor(y / 1.25));
if (x > 0 || y > 0) {
window.setTimeout("ReturnToTop()", 25);
}
} else {
//引数に入れたid名の場所へ(y軸限定)
if (window.opera) {
//でもOpera9未満は除外
var usrAge = navigator.userAgent;
var posStart = usrAge.indexOf("Opera",0);
var posEnd = usrAge.indexOf(" ",posStart+6);
if (posEnd <= 0) posEnd = usrAge.length;
var AgeVer = usrAge.substring(posStart+6,posEnd);
if (AgeVer < 9) {
window.open("#"+pos,"_self")
return false;
}
}
var isMSIE = /*@cc_on!@*/false;
var targetEle = document.getElementById(pos);

while( targetEle ){
y4 += targetEle.offsetTop;
targetEle = targetEle.offsetParent;
//IEの補正：上記計算で無視されてしまう各親要素のborder幅を加算
if ((targetEle) && (isMSIE)) {
y4 += (parseInt(getElementStyle(targetEle,"borderTopWidth","border-top-width")) || 0);
}
}

var y5 = y4-y;
y += Math.floor(y5 / 5);
window.scrollTo(x, y);
if ((!now || now != y)&&(y > y4-5 || y < y4-5)) {
window.setTimeout('ReturnToTop("'+pos+'","'+y+'")', 25);
}
}
}
function getElementStyle(targetElm,IEStyleProp,CSSStyleProp) {
var elem = targetElm;
if (elem.currentStyle) {
return elem.currentStyle[IEStyleProp];
} else if (window.getComputedStyle) {
var compStyle = window.getComputedStyle(elem,"");
return compStyle.getPropertyValue(CSSStyleProp);
}
}