var number = 0;
    var headPics = [];
    var fadeInterval = 4000;

    function rotate() 
    {
        // Берем первую картинку
        var currentPic = headPics[number];
        if (number < headPics.length - 1) 
        {
            var nextPic = headPics[number + 1];
            number = number + 1;
        }
        else if (number == headPics.length - 1) 
        {
            var nextPic = headPics[0];
            number = 0;
        }

        currentPic.animate({ opacity: 0.0 }, fadeInterval);
        nextPic.animate({ opacity: 1.0 }, fadeInterval);
    }

    $(document).ready(function() {

        headPics[0] = $('#headPic1');
        headPics[1] = $('#headPic2');
        headPics[2] = $('#headPic3');
        headPics[3] = $('#headPic4');
        setTimeout('rotate()', 2000);
        setInterval('rotate()', 5000);
    }
);