public ActionResult AssignRole(string[] roles, string id)
        {
            IRoleDao  roleDao = _factory.CreateRoleDao();
            UserGroup user    =
                _factory.CreateUserGroupDao().Get(id);

            user.Roles.Clear();
            foreach (Role role in roleDao.GetRolesByName(roles))
            {
                user.Roles.Add(role);
            }
            return(RedirectToAction("Index"));
        }