function getElementById(id) {
	return document.getElementById(id);
}

function scrollBanner(timer, moveNumber) {

function move(o) {
	var st = document.documentElement.scrollTop + o.t;
	var sl = document.documentElement.scrollLeft + (o.c == 0 ? o.a : document.documentElement.clientWidth - o.a - o.offsetWidth);
	var tc = st - o.offsetTop, lc = sl - o.offsetLeft;
	with (o.style) {
		top = o.offsetTop + (tc != 0 ? tc / Math.abs(tc) : 0) * Math.min(Math.abs(tc), moveNumber) + "px";
		left = o.offsetLeft + (lc != 0 ? lc / Math.abs(lc) : 0) * Math.min(Math.abs(lc), moveNumber) + "px";
	}
	if (o.person) {
		with (o.person.style) {
		top = o.offsetTop + "px";
		left = o.offsetLeft + o.offsetWidth - o.person.offsetWidth + "px";
		}
	}
}

var hidden = function() {
	var o = this.parent;
	window.clearInterval(o.interval);
	o.parentNode.removeChild(o);
	this.parentNode.removeChild(this);
}

this.add = function (to, t, a, c, lo) {
/*
to为object对象
t为距离顶端距离
当c = 0的时候，a为距离左边的距离
当c != 0的时候，a为距离右边的距离
lo为关闭按钮
*/
var div, exec = function () {
	move(to);
};

to.person = lo;
to.t = t;
to.a = a;
to.c = c;
with (to.style) {
	position = "absolute";
	display = "block";
	top = document.documentElement.scrollTop + t;
	left = document.documentElement.scrollLeft + (c == 0 ? a : document.documentElement.clientWidth - a - to.offsetWidth);
}

if ("undefined" != typeof lo) {
	with (lo.style) {
		position = "absolute";
		display = "block";
	}
	lo.onmousedown = hidden;
	lo.parent = to;
}
exec();
to.interval = window.setInterval(exec, timer);
};
}

window.onload = function () {
var b = new scrollBanner(10,15);
b.add(getElementById("lwc"), 200, 10, 0, getElementById("lwc_c"));

b.add(getElementById("rwc"), 200, 10, 1, getElementById("rwc_c"));

b = null;
}