var imgAt = 1;
var imgNext = 2;
var imgLast = 1;

function nextImage(){
  jQuery('#rotate_image' + String(imgAt)).fadeOut('slow', function() {});
  jQuery('#rotate_image' + String(imgNext)).fadeIn('slow', function() {});
  imgAt = imgNext;
  imgNext = imgNext + 1;
  if(imgNext > imgLast){
    imgNext = 1;
  }
}

$(document).ready(function(){
  imgLast = parseInt($('#rotate_image_count').val());
  if(imgLast > 1){
    setInterval("nextImage()", 8000);
  }
});