window.addEvent('domready',function() {
  /* settings */
  var showDuration = 30000;
  var containers = $$('div.slideshow-container');
  containers.each (function(container){
    var images = container.getElements('img');
    var currentIndex = 0;
    var interval;
    /* opacity and fade */
    images.each(function(img,i){ 
      if(i > 0) {
        img.set('opacity',0);
      }
    });
    var show = function() {
             images[currentIndex].fade('out');
             images[currentIndex = currentIndex < images.length - 1 ? currentIndex+1 : 0].fade('in');
           };
           window.addEvent('load',function(){
             interval = show.periodical(showDuration);
           });
  });
  /* worker */
  
  /* start once the page is finished loading */
  
});