function zk_change_tag(new_tab) {
    var new_active = $(new_tab);
    var active = $("#info-box-tab li a.active");
    
    active.removeClass('active');
    new_active.addClass('active');
    
    $("#content-" + active[0].id).hide();
    $("#content-" + new_active[0].id).show();
};

function zk_switch_page(old_page, new_page) {
    old_page.removeClass('active');
    var old_page_hash = old_page.find("a")[0].hash;
    $(old_page_hash).hide();
    
    new_page.addClass('active');
    var new_page_hash = new_page.find("a")[0].hash;
    $(new_page_hash).show();
};    

function zk_turn_page(trigger) {
    if (trigger.id=='') {
        var ht = trigger.href;
        var hash_index = ht.indexOf('#');
        var minus_index = ht.lastIndexOf('-');
        var tab_id = ht.substring(hash_index);
        var content_slug = ht.substring(hash_index+1, minus_index);
        var content_selector = '#content-' + content_slug + " .tabcontent";
        var li_selector = '#pag-' + content_slug + ' li';
        
        $(content_selector).hide();
        $(tab_id).show();
        
        $(li_selector).removeClass('active');
        $(trigger).parent().addClass('active');
        
    } else {
        var action = trigger.id.substring(0,4);
        var minus_index = trigger.id.indexOf('-');
        var content_slug = trigger.id.substring(minus_index+1);
        
        var lis = $('#pag-'+ content_slug + ' li');
        var list_len = lis.length;

        for (var i=0; i<list_len; i++) {
            active = $(lis[i]);
            if (active.hasClass('active')) {
                if (action=='prew' && i>0) {
                    zk_switch_page(active, $(lis[i-1]));
                    break;
                };
                
                if (action=='next' && i<(list_len-1)) {
                    zk_switch_page(active, $(lis[i+1]));
                    break;
                };
            };
        };
    };
};


$(document).ready(function() {
    $("#special_button").click(function(){
        document.location=$("#special_category option:selected")[0].value;
    });
    
    $("#expert_button").click(function(){
        document.location=$("#strucnjak option:selected")[0].value;
    });
    
    $(".pagination_new .prew, .pagination_new .next").click(function(){
        zk_turn_page(this);
        return false;
    });
    
    $(".pages_new ul li a").click(function(){
        zk_turn_page(this);
        return false;
    });
    
    $("#info-box-tab li a").click(function(){
        zk_change_tag(this);
        return false;
    });
});