CardChanger = {
    current: null,
    blockChange: false,

    init: function() {
        var hash = window.location.hash;

        if (hash.length == 0) {
            CardChanger.current = $('#subpages div:visible').eq(0);
        } else {
            var linkObj = $(hash);

            if (linkObj.length == 0) {
                window.alert('Podana strona nie istnieje');
                return false;
            } else {
                CardChanger.current = linkObj;
                $('#subpages div').hide();
                CardChanger.current.show();
            }
        }

        return true;
    },

    change: function(page) {
        if (CardChanger.blockChange) {
            return false;
        }

        CardChanger.blockChange = true;

        var next = $(page);
        
        CardChanger.current.fadeOut(500, function() {
            next.fadeIn(500, function() {
                CardChanger.blockChange = false;
            });
        });

        CardChanger.current = next;
        return true;
    }
}

$(function() {
    CardChanger.init();

    $('.menu a').each(function() {
        var $this = $(this);

        $this.click(function() {
            CardChanger.change($this.attr('href'));
        });
    });
});