// JavaScript Document
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');  } });
}, 6000);