Event.observe(window, 'load', function(){
	
    setInterval(function(){
      var imgs = $$('.slideshow img'), 
       visible = imgs.findAll(function(img){ return img.visible(); });
      if(visible.length>1) visible.last().fade({ duration: .3 });
        else imgs.last().appear({ duration: .3, 
          afterFinish: function(){ imgs.slice(0,imgs.length-1).invoke('show');  } });
    }, 3000);

});