public User Login() // returns an instance of its own class
        {
            var us = ie.users.FirstOrDefault(u => u.emailaddress == emailaddress);

            User user = new User();

            if (us == null)
            {
                throw new Exception("Invalid email address and/or password.");
            }

            if (Hashing.ValidatePassword(password, us.password))
            {
                user.userid = us.userid;
                user.storeid = us.storeid;
                user.role = us.role;
            }
            else
            {
                throw new ValidationException("Invalid email address and/or password.");
            }

            return user;
        }