var navBtnsOn = new Array();

window.onload = function(){
	var folder = "nav/";
	var navBtnStrs = new Array('o1', 'o2', 'o3', 'o4', 'o5', 'o6', 'o7', 'o8', 'o9', 'f1', 'f2', 'f3', 'f4', 'f5', 'f6', 'f7', 'f8', 'f9', 'f10', 'f11', 'f12', 'f13', 'f14', 'a1', 'a2', 'a3', 'a4', 'a5', 'a6', 'a7', 'a8');
	var navBtns = new Array();
	for(var i in navBtnStrs){
		var navBtn = new NavElement(navBtnStrs[i], folder);
		navBtns[navBtnStrs[i]] = navBtn;
	}
	for(var i in navBtnsOn){
		navBtns[navBtnsOn[i]].setOn();
	}
}

function navImage(id, folder){
	var baseFolder = folder;
	this.imgOn = new Image();
	this.imgOn.src = baseFolder + id + "_on.gif";
	this.imgOff = new Image();
	this.imgOff.src = baseFolder + id + ".gif";
}

function NavElement(id, folder){
	this.id = id;
	if(document.getElementById && document.getElementById(id)){
		var domEl = document.getElementById(id);
		domEl.NavElement = this;
		if (document.images) {
			this.imgObj = new navImage(id, folder);
			domEl.onmouseover = NavElement.eMouseOver;
			domEl.onmouseout = NavElement.eMouseOut;
		}
	}
}
NavElement.eMouseOver = function(e){
	document.getElementById(this.id).src = this.NavElement.imgObj.imgOn.src;
}
NavElement.eMouseOut = function(e){
	document.getElementById(this.id).src = this.NavElement.imgObj.imgOff.src;
}
NavElement.prototype.setOn = function(){
	if(document.getElementById && document.getElementById(this.id)){
		var domEl = document.getElementById(this.id);
		domEl.src = this.imgObj.imgOn.src;
		domEl.onmouseover = null;
		domEl.onmouseout = null;
	}
}