setInterval(function(){
	var imgs = $$('.fadein img'),
	visible = imgs.findAll(function(img){ return img.visible(); });
	if(visible.length>1) visible.last().fade({ duration: .9 });
	else imgs.last().appear({ duration: .9,
	afterFinish: function(){ imgs.slice(0,imgs.length-1).invoke('show');  } });
}, 9000);