var Sideshow = function(box){	
	
	var current = 0;	
	var $chk = function(obj){
	    return !!(obj || obj === 0);
	};
	var first = true;

	var go = function(){		
		
		
		var items = box.getElements('span');
		
		items[current].set('tween', {duration: 'long'});
		items[current].tween('opacity',[0,1]);
		
		if(first){
			first = false;			
		}else{
			
			prev.set('tween', {duration: 'long'});
			prev.tween('opacity',[1,0]);
		}
		
		prev = items[current];
		current++;
		if(current==items.length){
			current = 0;
		}
	};
	
	go();
	var timeoutID = go.periodical(4000);

	
};