// 1) Linkup prototype.js, effects.js, slide_img.js in the head tab

// 2) Add fadein and fadein img in your css

// 3) Paste all image tab inside the div tab, and naming the div called fadein


setInterval(function(){
  var imgs = $$('.fadein 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');  } });
}, 5000);