// ##########

// Functionaliteit getElemetsByClass
// http://www.alistapart.com

// ARRAY EXTENSIONS

if (!Array.prototype.push) Array.prototype.push = function() {
    for (var i=0; i<arguments.length; i++) this[this.length] = arguments[i];
    return this.length;
}

Array.prototype.find = function(value, start) {
    start = start || 0;
    for (var i=start; i<this.length; i++)
        if (this[i]==value)
            return i;
    return -1;
}

Array.prototype.has = function(value) {
    return this.find(value)!==-1;
}

// FUNCTIONAL

function map(list, func) {
    var result = [];
    func = func || function(v) {return v};
    for (var i=0; i < list.length; i++) result.push(func(list[i], i, list));
    return result;
}

function filter(list, func) {
    var result = [];
    func = func || function(v) {return v};
    map(list, function(v) { if (func(v)) result.push(v) } );
    return result;
}


// DOM

function getElem(elem) {
    if (document.getElementById) {
        if (typeof elem == "string") {
            elem = document.getElementById(elem);
            if (elem===null) throw 'cannot get element: element does not exist';
        } else if (typeof elem != "object") {
            throw 'cannot get element: invalid datatype';
        }
    } else throw 'cannot get element: unsupported DOM';
    return elem;
}

function hasClass(elem, className) {
    return getElem(elem).className.split(' ').has(className);
}

function getElementsByClass(className, tagName, parentNode) {
    parentNode = !isUndefined(parentNode)? getElem(parentNode) : document;
    if (isUndefined(tagName)) tagName = '*';
    return filter(parentNode.getElementsByTagName(tagName),
        function(elem) { return hasClass(elem, className) });
}


// DOM EVENTS

function listen(event, elem, func) {
    elem = getElem(elem);
    if (elem.addEventListener)  // W3C DOM
        elem.addEventListener(event,func,false);
    else if (elem.attachEvent)  // IE DOM
        elem.attachEvent('on'+event, function(){ func(new W3CDOM_Event(elem)) } );
        // for IE we use a wrapper function that passes in a simplified faux Event object.
    else throw 'cannot add event listener';
}

function mlisten(event, elem_list, func) {
    map(elem_list, function(elem) { listen(event, elem, func) } );
}

function W3CDOM_Event(currentTarget) {
    this.currentTarget  = currentTarget;
    this.preventDefault = function() { window.event.returnValue = false }
    return this;
}


// MISC CLEANING-AFTER-MICROSOFT STUFF

function isUndefined(v) {
    var undef;
    return v===undef;
}

// ##########

// Werkt met getElementsByClass
// var imgs = getElementsByClass('mouseover', 'img');

// original script by Peter-Paul Koch
// (http://www.quirksmode.org/) 

var W3CDOM = (document.createElement && document.getElementsByTagName);

var mouseOvers = new Array();
var mouseOuts = new Array();

function init()
{
	if (!W3CDOM) return;
	var imgs = getElementsByClass('mouseover', 'img');
	for (var i=0;i<imgs.length;i++)
	{
		imgs[i].onmouseover = mouseGoesOver;
		imgs[i].onmouseout = mouseGoesOut;
		var suffix = imgs[i].src.substring(imgs[i].src.lastIndexOf('.'));
		mouseOuts[i] = new Image();
		mouseOuts[i].src = imgs[i].src;
		mouseOvers[i] = new Image();
		mouseOvers[i].src = imgs[i].src.substring(0,imgs[i].src.lastIndexOf('.')) + "_omo" + suffix;
		imgs[i].number = i;
	}
}

function mouseGoesOver()
{
	this.src = mouseOvers[this.number].src;
}

function mouseGoesOut()
{
	this.src = mouseOuts[this.number].src;
}