function slideSwitch() {
    var $active = $('#slideshow IMG.active').removeClass('active').hide();
    var $next =  $active.next().length ? $active.next() : $('#slideshow IMG:first');
    $next.css({opacity: 0.0})
        .addClass('active').show()
        .animate({opacity: 1.0}, 1000, function() {
            $active.removeClass('active last-active');
        });
}

$(function(){ setInterval("slideSwitch()", 5000); });