$(document).ready(function(){

		$('.nivel3').hide();
		$('.nivel3').attr('rel','hidden');
		
    $('.nivel2').click(function()
	{
		var rel = '.id'+$(this).attr('rel');
		var visibility = $(rel).attr('rel');
		
			$('.nivel3').hide('slow');
			$('.nivel3').attr('rel','hidden');
			
		if(visibility == 'hidden')
			{
			$(rel).show('slow');
			$(rel).attr('rel','visible');
			}
        }
    );


});