// http://www.rob-watson.co.uk/?page=38#xhtml


function setOpacity(el, opacity) {

    //  Which opacity method does this browser support?

    opacity /= 100;

    el.style.opacity = opacity;
    el.style.MozOpacity = opacity;
    el.style.filter = "alpha(opacity=" + (opacity*100) + ")";

}

function fadeImage(el, currentOpacity) {

    currentOpacity += 5;

    if (currentOpacity > 100) {
        setOpacity(el, 100);
        var prevEl = el.previousSibling ? el.previousSibling : el.parentNode.lastChild;
        prevEl.style.visibility = 'hidden';
        el.style.zIndex = 1;
        window.setTimeout(startFading, imageTimeout);
    }
    else {
        setOpacity(el, currentOpacity);
        window.setTimeout(function() {
            fadeImage(el, currentOpacity);
        }, 50);
    }

}


function startFading() {

    var el = document.getElementById('blockright').childNodes[nextImage];

    el.style.visibility = 'visible';
    el.style.zIndex = 2;
    setOpacity(el, 0);
    fadeImage(el,0);

    nextImage = (nextImage < images.length-1) ? nextImage + 1 : 0;

}


function pageLoad() {

    var el = document.getElementById('blockright');

    while (el.firstChild) {
        el.removeChild(el.firstChild);
    }

    el.style.width = imageWidth + 'px';
    el.style.height = imageHeight + 'px';

    for(var i=0; i<images.length; i++) {

        var t = document.createElement('img');
        t.setAttribute('src',images[i]);
        t.setAttribute('width',imageWidth);
        t.setAttribute('height',imageHeight);
        t.style.position = 'absolute';
        t.style.visibility = 'hidden';
        el.appendChild(t);

    }

    el.firstChild.style.visibility = 'visible';
    window.setTimeout(startFading, imageTimeout);    

}

window.onload = pageLoad;