img_on = new Image(); img_on.src="/images/menu/on.gif";
img_off = new Image(); img_off.src="/images/menu/off.gif";

function obj_br(){
	this.dom = document.getElementById ? true : false;
	this.opera = navigator.userAgent.indexOf("Opera") > -1;
	this.ie = (document.all && !this.opera) ? true : false;
	this.ns = (document.layers && !this.dom) ? true : false;
	this.en = (this.ie || this.ns || this.opera || this.dom);

	return this;
};
br = new obj_br();

function css(id) {
	if (br.dom) return document.getElementById(id).style
	else if (br.ie) return document.all[id].style
	else if (bw.ns) return document[id]
	else return false;
};

sel_id = null;
function cl(id) {
	if (sel_id != null) {
		obj = css('sub_' + sel_id);
		obj.display = 'none';
	};
	obj = css('sub_' + id);
	obj.display = 'block';
	sel_id = id;
};