(function () {
     function enableTransition (element) {
	 element.style.webkitTransitionProperty = 'left';
	 element.style.mozTransitionProperty = 'left';
	 element.style.oTransitionProperty = 'left';
     }
     
     function disableTransition (element) {
	 element.style.webkitTransitionProperty = 'none';
	 element.style.mozTransitionProperty = 'none';
	 element.style.oTransitionProperty = 'none';
     }

     window.onload = function () {
	 var elements = document.querySelectorAll('.slider');
	 Array.prototype.slice.call(elements)
	     .forEach(function (element) {
			  var images = element.querySelectorAll('img');
			  var count = images.length;
			  var index = 0;
			  function slide () {
			      var other = images[(index + 2) % count];
			      disableTransition(other);
			      other.setAttribute('class', '');
			      var current = images[index % count];
			      enableTransition(current);
			      current.setAttribute('class', 'past');
			      var next = images[(index + 1) % count];
			      enableTransition(next);
			      next.setAttribute('class', 'current');
			      index++;
			  }
			  var current = images[index % count];
			  disableTransition(current);
			  current.setAttribute('class', 'current');			  
			  setInterval(slide, 5000);
		      });
     };
 })();