function fold_unfold(i) {
	$('#link_' + i).mouseover(function() {
		$('#group_' + i).removeClass('fold');
		$('#group_' + i).addClass('unfold');
	});
	$('#link_' + i).mouseout(function() {
		$('#group_' + i).removeClass('unfold');
		$('#group_' + i).addClass('fold');
	});
}

$(document).ready(function() {
	
	fold_unfold(1);
	fold_unfold(2);
	fold_unfold(3);
	fold_unfold(4);
	fold_unfold(5);
	fold_unfold(6);
	fold_unfold(7);
	fold_unfold(8);
	
});