function displaySubMenu(obj){
	obj.className = 'active';
	if(obj.lastChild.className == 'second_niveau'){
		obj.lastChild.style.display = 'block';
	}
	return true;
}

function hideSubMenu(obj){
	obj.className = '';
	if(obj.lastChild.className == 'second_niveau'){
		obj.lastChild.style.display = 'none';
	}
	return true;
}