//If the browser is W3 DOM compliant, execute setImageSwaps function
if (document.getElementsByTagName && document.getElementById) {
    if (window.addEventListener) window.addEventListener('load', setImageSwaps, false);
    else if (window.attachEvent) window.attachEvent('onload', setImageSwaps);
}

//When document loads, apply the prepareImageSwap function to various images with our desired settings
function setImageSwaps() {
    //Mousedown, restore - for images in container with ID=example2
   //========= prepareImageSwap('example2', true, true, true, true);
    //Hover, mousedown, no restore - for images in container with ID=example3
    //========prepareImageSwap('example3', true, false, true, false);
    //Hover with restore, most basic usage - for any image in document.body that are not yet processed (function accepts elements,too)
    prepareImageSwap(document.body);
    //Note that once an image is processed, it won't be processed again, so you should set more specific images first, e.g. document.body, as it is the grand
    //container, has to be processed last.
}


//The following is the function that do the actual job

function prepareImageSwap(elem, mouseOver, mouseOutRestore, mouseDown, mouseUpRestore, mouseOut, mouseUp) {
    //Do not delete these comments.
    //Non-Obtrusive Image Swap Script by Hesido.com
    //V1.1
    //Attribution required on all accounts
    if (typeof (elem) == 'string') elem = document.getElementById(elem);
    if (elem == null) return;
    var regg = /(.*)(_nm\.)([^\.]{3,4})$/
    var prel = new Array(), img, imgList, imgsrc, mtchd;
    imgList = elem.getElementsByTagName('img');

    for (var i = 0; img = imgList[i]; i++) {
        if (!img.rolloverSet && img.src.match(regg)) {
            mtchd = img.src.match(regg);
            img.hoverSRC = mtchd[1] + '_hv.' + mtchd[3];
            img.outSRC = img.src;
            if (typeof (mouseOver) != 'undefined') {
                img.hoverSRC = (mouseOver) ? mtchd[1] + '_hv.' + mtchd[3] : false;
                img.outSRC = (mouseOut) ? mtchd[1] + '_ou.' + mtchd[3] : (mouseOver && mouseOutRestore) ? img.src : false;
                img.mdownSRC = (mouseDown) ? mtchd[1] + '_md.' + mtchd[3] : false;
                img.mupSRC = (mouseUp) ? mtchd[1] + '_mu.' + mtchd[3] : (mouseOver && mouseDown && mouseUpRestore) ? img.hoverSRC : (mouseDown && mouseUpRestore) ? img.src : false;
            }
            if (img.hoverSRC) { preLoadImg(img.hoverSRC); img.onmouseover = imgHoverSwap; }
            if (img.outSRC) { preLoadImg(img.outSRC); img.onmouseout = imgOutSwap; }
            if (img.mdownSRC) { preLoadImg(img.mdownSRC); img.onmousedown = imgMouseDownSwap; }
            if (img.mupSRC) { preLoadImg(img.mupSRC); img.onmouseup = imgMouseUpSwap; }
            img.rolloverSet = true;
        }
    }

    function preLoadImg(imgSrc) {
        prel[prel.length] = new Image(); prel[prel.length - 1].src = imgSrc;
    }

}

function imgHoverSwap() { this.src = this.hoverSRC; }
function imgOutSwap() { this.src = this.outSRC; }
function imgMouseDownSwap() { this.src = this.mdownSRC; }
function imgMouseUpSwap() { this.src = this.mupSRC; }