function change(what){
    var active = what.filter('.active');
    if (active.length == 0)
        active = what.filter(':last');

    var next = active.next().length ? active.next() : what.filter(':first');

    active.addClass('prev');

    active.animate({
        opacity: 0.0
    }, 1000);

    next.css({
        opacity: 0.0
    }).addClass('active').animate({
        opacity: 1.0
    }, 1000, function(){
        active.removeClass('active prev');
    });
}

$(function(){
    var siedziba = $('#siedziba a');
    siedziba.fancybox();

    change(siedziba);
    $(window).everyTime(4000, function(){
        change(siedziba);
    })
    
});