function opening() {
	$('a[data-opens]').click(function() {
		
		var openedby = $(this).attr('data-opens');
		$('[data-openedby="' + openedby +'"]').removeClass('off').addClass('on');
		
		var closedby = $(this).attr('data-closes');
		$('[data-closedby="' + closedby +'"]').css('display', 'none');
		
		$(this).addClass('clicked');
		
	});
}