function rollover(image) {
	var overstr = /_o\./;
	var normalstr = /_n\./;
	
	if (!image.src) {
		image = document.getElementById(image);
	}
	var imagesrc = image.src;
	
	image.src = normalstr.test(imagesrc) ? imagesrc.replace(normalstr,"_o.") : imagesrc.replace(overstr,"_n.");
	return true;
}

function preloadImages(images) {
	
	var imgDir = "resources/images/";
	
	var preloadImage = new Array;
	
	
	
	for ( var i = 0; i < images.length; i++ ) {
		preloadImage[i] = new Image;
		preloadImage[i].src = imgDir + images[i];
	}


}



var timerID = null;
var timerOn = false;
var timecount = 200;

function menuShow(menuItem, trigger) {
	
	var headerHeight = 128;
	var headerWidth = 5;
	
	var agt = navigator.userAgent.toLowerCase();
	
	var is_ie     = ((agt.indexOf("msie") != -1) && (agt.indexOf("opera") == -1));
	var is_major = parseInt(navigator.appVersion);
	var is_ie4up  = (is_ie && (is_major >= 4));
	
	var locTop = 0;
	var locLeft = 0;
	
	if (is_ie4up) {
		locTop = headerHeight;
		locLeft = trigger.offsetLeft + headerWidth;
	} else {
		locTop = headerHeight;
		locLeft = trigger.offsetLeft + headerWidth;
	}
	
	
	
	
	document.getElementById(menuItem).style.position = 'absolute';
	document.getElementById(menuItem).style.top = locTop + 'px';
	document.getElementById(menuItem).style.left = locLeft + 'px';
	document.getElementById(menuItem).style.display = 'block';
	
	/*
	menuItem.style.position = 'absolute';
	menuItem.style.top = locTop + 'px';
	menuItem.style.left = locLeft + 'px';
	menuItem.style.display = 'block';
	*/
}

function menuHide() {

		menuItems = document.getElementById('menus').childNodes;
		
		for (i=0; i<menuItems.length; i++) {
		
			if (menuItems[i].className == "menu") {
				menuItems[i].style.display = 'none';
			}
		}

		
}

function startTimer() {
	if (timerOn == false) {
		timerID = setTimeout( "menuHide()" , timecount);
		timerOn = true;
	}
}

function stopTimer() {
	if (timerOn) {
		clearTimeout(timerID);
		timerID = null;
		timerOn = false;
	}
}


/* todo: more elegant menu function 
function showMenu(name) {
	menuName = document.getElementById('menu' + name);
	btnName = document.getElementById('btn' + name);
	
	
	
	menuHide();
	stopTimer();
	
	
	
	
	var normalstr = /_n\./;
	btnName.src = btnName.src.replace(normalstr,"_o.");
	
	menuShow(menuName, btnName);
	

}

function hideMenu(name) {


}
*/