//jQuery.noConflict()
var duration = 3;

function fadeInOut(img){
  $(img).fadeIn(500,
    function(){
      setTimeout(function(){
        $(img).fadeOut(500,
          function(){fadeInOut(img.next)})
        }, 4000
      )
    }
  );
}

function slideshow(tagname) {
  var imgs = $("." + tagname + " img");

  for(var i = 0; i < imgs.length ; i++){
    imgs[i].next = imgs[(i+1) % imgs.length];
  }

  fadeInOut(imgs[0]);
}