$(document).ready(function () {

    /* This code is executed after the DOM has been completely loaded */

    var totWidth = 0;

    var positions = new Array();

    $('#slides .slide').each(function (i) {

        /* Traverse through all the slides and store their accumulative widths in totWidth */

        positions[i] = totWidth;

        totWidth += $(this).width();

        /* The positions array contains each slide's commulutative offset from the left part of the container */

        if (!$(this).width()) {

            alert("Please, fill in width & height for all your images!");

            return false;
        }

    });

    $('#slides').width(totWidth);

    /* Change the cotnainer div's width to the exact width of all the slides combined */

    $('#menu ul li a').click(function (e, keepScroll) {

        /* On a thumbnail click */

        $('li.menuItem').removeClass('act').addClass('inact');

        $(this).parent().addClass('act');

        var pos = $(this).parent().prevAll('.menuItem').length;

        $('#slides').stop().animate({ marginLeft: -positions[pos] + 'px' }, 450);

        /* Start the sliding animation */

        e.preventDefault();

        /* Prevent the default action of the link */

        // Stopping the auto-advance if an icon has been clicked:

        if (!keepScroll) clearInterval(itvl);

    });

    $('#menu ul li.menuItem:first').addClass('act').siblings().addClass('inact');

    /* On page load, mark the first thumbnail as active */

    /*****

    *

    *	Enabling auto-advance.

    *

    ****/

    var current = 1;

    function autoAdvance() {

        if (current == -1) return false;

        $('#menu ul li a').eq(current % $('#menu ul li a').length).trigger('click', [true]); // [true] will be passed as the keepScroll parameter of the click function on line 28

        current++;

    }

    // The number of seconds that the slider will auto-advance in:

    var changeEvery = 10;

    var itvl = setInterval(function () { autoAdvance() }, changeEvery * 500);

    /* End of customizations */

});