// Util

function eventTarget(e) {
	var target;
		
	if (e.target)
		target = e.target;
	else if (e.srcElement)
		target = e.srcElement;
		
	//safari
	if (target.nodeType == 3)
		target = target.parentNode;
		
	return target;
}

// Rollovers

var rolloverType = '.gif';
var rolloverSuffix = '_over';

function rollover(e){
	if (!e) var e = window.event;
	var target = eventTarget(e);
	var basename = target.src.substring(0, target.src.length - rolloverType.length);
	target.src = basename + rolloverSuffix + rolloverType;
}

function rollout (e) {
	if (!e) var e = window.event;	
	var target = eventTarget(e);
	var basename = target.src.substring(0, target.src.length - (rolloverSuffix.length + rolloverType.length));
	target.src = basename + rolloverType;
}

function addListeners () {
	// header rollovers
	var header = document.getElementById('header');
	for (var i=0; i < header.childNodes.length; i++) {
		var child = header.childNodes[i];
		if(
			child.tagName == 'A' &&
			child.childNodes[0] &&
			child.childNodes[0].tagName == 'IMG'
		){
			child.childNodes[0].onmouseover = rollover;
			child.childNodes[0].onmouseout = rollout;
		}
	}	
}