function slideSwitch() {
    var $active = $('#slideshow img.active');

    if ( $active.length == 0 ) $active = $('#slideshow img:last');

    var $next =  $active.next().length ? $active.next()
        : $('#slideshow img:first');

    $active.addClass('last-active');

    $next.css({opacity: 0.0})
        .addClass('active')
        .animate({opacity: 1.0}, 2000, function() {
            $active.removeClass('active last-active');
        });
}

var initSlideShow = function() {
    if($('#slideshow').length == 1) {
        // nur einmal wechseln:
        //setTimeout('slideSwitch()', 4000);
        setInterval('slideSwitch()', 6000 );
    }
}

$(document).ready(function() {
    initSlideShow();
});