$(function(){
	var index = 0;
	var target = $('#immagini img');
	var n = target.length-1;
	target.css('display','none');
	$(target.get(0)).css('display','block');	
	$('#sx').css('cursor','pointer').click(function(event){				   		
						   		$(target.get(index)).css('display','none')			
								$(target.get(next(index,-1))).css('display','block');
								//alert(index+"__"+next(index,-1));									
								index = next(index,-1);
						   });
	$('#dx').css('cursor','pointer').click(function(event){				   		
						   		$(target.get(index)).css('display','none')			
								$(target.get(next(index,1))).css('display','block');
								//alert(index+"__"+next(index,1));									
								index = next(index,1);							
						   });
	
	function next(id,verso){
					if (((id < n)&&(id > 0))||(id==0)&&(verso==1)) { 
							return id+verso;
					} else { 
						if (id == n) { 					
							return id=0; 
						} else { 					
							return id=n; 
						} 
					};					
		}
});