public static void UpdatePwd(int loginid, string pwdhash)
        {
            // Connect to database
            SqlConnection connection = DALConnection.GetConnectionByName("Writer");
            connection.Open();

            // Maak SQL string
            string sqlString = ("UPDATE Login SET PwdHash = @pass WHERE LoginId = @id");

            // Command
            SqlCommand command = new SqlCommand(sqlString, connection);

            // Parameters
            SqlParameter LoginIdParameter = new SqlParameter("@id", SqlDbType.Int);
            SqlParameter PwdHashParameter = new SqlParameter("@pass", SqlDbType.NChar,32);

            // Command parameter
            command.Parameters.Add(LoginIdParameter);
            command.Parameters.Add(PwdHashParameter);

            // voeg waarde toe aan parameter
            PwdHashParameter.Value = pwdhash;
            LoginIdParameter.Value = loginid;

            // prepare
            command.Prepare();

            // Voer gevulde query uit
            command.ExecuteNonQuery();

            // Connectie sluiten
            connection.Close();
        }

        public static int GetLoginId(int persoonid, string pwdhash)
        {
            SqlConnection connection = DALConnection.GetConnectionByName("Reader");
            connection.Open();

            // select string
            string sqlString = ("SELECT LoginId FROM Login WHERE PersoonId = '" + persoonid + "' AND PwdHash = '" + pwdhash + "'");

            // Command
            SqlCommand command = new SqlCommand(sqlString, connection);

            // Prepare
            command.Prepare();

            // Returnwaarde
            return (int)command.ExecuteScalar();
        }