(function($) {

    /**
     * Delays elements on scroll.
     * Used for creating a parallax effect.
     *
     * @param element
     * @param options
     */
    $.clientSlider = function(element, options) {

        var defaults = {

        };

// Reference to this
        var t = this;

// Create settings object
        t.settings = {};

// Elements
        var $ul = $('ul',element);

// Properties
        var cIndex = 0;
        var num;

// Constructor
        t.init = function ()
        {
            // Extend the defaults with options, save in settings
            t.settings = $.extend({}, defaults, options);

            num = $ul.children('li').size();
        };

        t.next = function()
        {
            // Goto
            if(cIndex != (num-3)) // 3 visible)
            {
                goto(cIndex+1);
            }
        };

        t.prev = function()
        {
            // Goto
            if(cIndex != 0) // 3 visible)
            {
                goto(cIndex-1);
            }
        };

        var checkButtons = function()
        {
            console.log(cIndex);
            // Disable next button
            if(cIndex == (num-3))
            {
                $('#next').addClass('disabled');
            }
            else
            {
                $('#next').removeClass('disabled');
            }

            // Disable next button
            if(cIndex == 0)
            {
                $('#prev').addClass('disabled');
            }
            else
            {
                $('#prev').removeClass('disabled');
            }

        };

        var goto = function(tIndex)
        {
            var $li = $ul.children('li');
            var top = -tIndex * ($li.height() + 20); // 20px marge

            $ul.stop().animate({ top: top+'px' },600);

            cIndex = tIndex;
            checkButtons();
        };

        t.init();

    };

    // Extend Jquery with function
    $.fn.clientSlider = function(options)
    {
        return this.each(function()
        {
            // if plugin has not already been attached to the element
            if ($(this).data('cs') == undefined)
            {
                // create a new instance of the plugin
                var clientSlider = new $.clientSlider(this, options);
                $(this).data('cs', clientSlider);
            }
        });
    }
})(jQuery);