public UserModel()
 {
     User = new User();
     UserRoleIds = new List<int>();
     AvailableRoles = new List<Role>();
 }
        public User UpdateUser(User user)
        {
            var entity = UnitOfWork.Users.GetById(user.Id);

            entity.Discount = user.Discount;
            entity.EmailAddress = user.EmailAddress;
            entity.Name = user.Name;
            entity.IsActive = user.IsActive;

            UnitOfWork.Users.Update(entity);
            UnitOfWork.Commit();

            return user;
        }