function getcookieval(offset)   {
        var endstr = document.cookie.indexOf(";",offset);
        if (endstr == -1)
                endstr = document.cookie.length;
        return unescape (document.cookie.substring(offset,endstr));
}

function getCookie(name)
{
    var arr = document.cookie.match(new RegExp("(^| )"+name+"=([^;]*)(;|$)"));
    if(arr != null) return unescape(arr[2]); return null;
}

if(getCookie("bgSrcUrl"))
document.body.style.backgroundImage='url('+getCookie("bgSrcUrl")+')';

function goTop(acceleration, time) {
	acceleration = acceleration || 0.1;
	time = time || 10;
 
	var x1 = 0;
	var y1 = 0;
	var x2 = 0;
	var y2 = 0;
	var x3 = 0;
	var 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;
	}
	var x3 = window.scrollX || 0;
	var y3 = window.scrollY || 0;
 
	// 滚动条到页面顶部的水平距离
	var x = Math.max(x1, Math.max(x2, x3));
	// 滚动条到页面顶部的垂直距离
	var y = Math.max(y1, Math.max(y2, y3));
 
	// 滚动距离 = 目前距离 / 速度, 因为距离原来越小, 速度是大于 1 的数, 所以滚动距离会越来越小
	var speed = 1 + acceleration;
	window.scrollTo(Math.floor(x / speed), Math.floor(y / speed));
 
	// 如果距离不为零, 继续调用迭代本函数
	if(x > 0 || y > 0) {
		var invokeFunction = "goTop(" + acceleration + ", " + time + ")";
		window.setTimeout(invokeFunction, time);
	}
}