window.addEvent('domready',function() {

if($('carousel')) {
  var showDuration = 4000;
  var container = $('carousel');
  var images = container.getElements('.slide');
  var currentIndex = 0;
  var interval;
  
  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);
  });
} 

});