var current_teaser_image = -1;

var teaser_gallery = function() {

    if (current_teaser_image > -1) {
        $('#teaser-' + current_teaser_image).fadeOut(1200);
    }

    if (++current_teaser_image > 3) {
        current_teaser_image = 0;
    }
    
    $('#teaser-' + current_teaser_image).fadeIn(1200);

    window.setTimeout('teaser_gallery()', 6 * 1000);
}

teaser_gallery();