public static Boolean isValidUser(string email, string password)
        {
            CustomMembership.MembershipProvider provider_instance = new CustomMembership.MembershipProvider();
            OleDbConnection conn = new OleDbConnection();

            conn.ConnectionString = ConfigurationManager.ConnectionStrings["database"].ToString();
            OleDbCommand cmd = new OleDbCommand();


            try
            {
                cmd.Connection = conn;
                conn.Open();


                cmd.CommandText = "SELECT email, wachtwoord " +
                                  "FROM account " +
                                  "WHERE email LIKE @_email;";

                cmd.Parameters.AddWithValue("@_email", email);


                OleDbDataReader reader = cmd.ExecuteReader();


                while (reader.Read())
                {
                    string temp_email    = reader[0].ToString();
                    string temp_password = reader[1].ToString();

                    string salt = temp_password.Substring(0, 64);
                    string hash = temp_password.Substring(64, 64);

                    string i_password = provider_instance.Sha256Hex(salt + password);

                    string _password = temp_password.Substring(64);

                    if (i_password == _password)
                    {
                        reader.Close();
                        conn.Close();
                        return(true);
                    }
                    else
                    {
                    }
                }

                reader.Close();
            }
            catch (Exception ex)
            {
            }
            finally
            {
                conn.Close();
            }
            return(false);
        }
        public static void saveData(string email, string password, int gameId, int score)
        {
            CustomMembership.MembershipProvider provider_instance = new CustomMembership.MembershipProvider();

            OleDbConnection conn = new OleDbConnection();

            conn.ConnectionString = ConfigurationManager.ConnectionStrings["database"].ToString();
            OleDbCommand cmd = new OleDbCommand();

            StreamWriter writer = new System.IO.StreamWriter("C:\\Users\\IEUSER\\Desktop\\logfile.txt");

            writer.WriteLine("Method saveData called");
            writer.Close();

            if (isValidUser(email, password))
            {
                try
                {
                    cmd.Connection = conn;
                    conn.Open();


                    cmd.CommandText = "INSERT INTO speelt(spel_id, email, score, time_stamp) VALUES(@_spel_id, @_email, @_score, @_time_stamp)";

                    DateTime now      = DateTime.Now;
                    String   time_now = now.ToString();

                    cmd.Parameters.AddWithValue("@_spel_id", gameId);
                    cmd.Parameters.AddWithValue("@_email", email);
                    cmd.Parameters.AddWithValue("@_score", score);
                    cmd.Parameters.AddWithValue("@time_stamp", 0);


                    int rows_added = cmd.ExecuteNonQuery();
                }
                catch (Exception ex)
                {
                }
                finally
                {
                    conn.Close();
                }
                //}

                //end
            }
        }