(function($) { 
  $(document).ready(function () {
    if ($('#rotator').length > 0) {
      
      var totalImages = $('#rotator img').length;
      var imagesArrayIDs = Array();
      
      $('#rotator img').each(function (i, element) {
        imagesArrayIDs[i] = $(element).attr('id');
      });
      imagesArrayIDs.sort(randomOrder);
      
      setInterval(changeImage, 4000);
    }
    
    function randomOrder() {
      return (Math.round(Math.random())-0.5);
    }
    
    var currentIndex = 0;
    function changeImage() {
      currentIndex++;
      var $nextImage = $('#rotator #'+ imagesArrayIDs[currentIndex]);
      
      $('#rotator img').hide();
      $nextImage.show();
      
      if (currentIndex == totalImages-1) {
        currentIndex = 0;
      }
    }
    
  });

})(jQuery);