window.addEvent("domready", function() {	
    var duration = 4000,
        container = $("slideshow-container"),
        images = container.getElements("img"),
        currentIndex = 0,
        interval;

    images.each(function(img, i) {
        if (i > 0) {
            img.set("opacity", 0);
        }
    });
    
    var show = function() {
        // images[currentIndex++].fade("out");
        // images[currentIndex %= images.length].fade("in");
        images[currentIndex++].set("tween", {
            duration: 2000
        }).tween("opacity", 0);
        images[currentIndex %= images.length].set("tween", {
            duration: 2000
        }).tween("opacity", 1);
    }
        
    show.periodical(duration);

});