window.addEvent('domready',function() {
  /* settings */
  var showDuration = 5000;
  var container = $('tn_slideshowContainer');
  var images = container.getElements('img');
  var currentIndex = 0;
  var interval;
 
  var captionDIV = new Element('div',{
	    id: 'tn_slideshowContainerCaption',
	    styles: {	      
	      opacity: 0.7
	    }
  }).inject(container);
  
  var captionHeight = captionDIV.getSize().y;
  captionDIV.setStyle('height', 0);
  
  /* opacity and fade */ 
  images.each(function(img,i){
	  if(i > 0) {
      img.set('opacity',0);
    }
  });
  
  //first round
  captionDIV.tween('height', '30px');
  title = images[currentIndex].get('alt');
  captionDIV.set('html', title);
   
  
  /* do the work */
  var show = function() {    
		
	//captionDIV.setStyle('height', 0);
	  
	images[currentIndex].fade('out'); 
    images[currentIndex = currentIndex < images.length - 1 ? currentIndex+1 : 0].fade('in');    
    
    
    //captionDIV.tween('height', '40px');
    
    var caption = '';	
	if(images[currentIndex].get('alt')) {
	     caption = images[currentIndex].get('alt');	    
	     //captionDIV.set('html', caption);                    
	}
	
	 
  };
  /* start after the page is loaded */
  window.addEvent('load',function(){
    interval = show.periodical(showDuration);
  });
});