// JavaScript Document

var number_layer = 11;
var current_layer = 1;

function go_to_next_layer()
{
	fade(current_layer);
	current_layer = current_layer + 1;
	if(current_layer > number_layer)
	{
		current_layer = 1;
	};
	appear(current_layer);
};

function go_to_back_layer()
{
	fade(current_layer);
	current_layer = current_layer - 1;
	if(current_layer < 1)
	{
		current_layer = number_layer;
	};
	appear(current_layer);
};

function appear(i)
{
		$('layer' + i).appear();	
};

function fade(i)
{
		$('layer' + i).fade();	
};

window.setInterval("go_to_next_layer()", 4000);