private void readCard_Click(object sender, EventArgs e)
        {
            uint card_id   = 0;
            int  custom_id = 0;

            Cursor.Current = Cursors.WaitCursor;

            int result = BSSDK.BS_ReadCardIDEx(m_Handle, ref card_id, ref custom_id);

            Cursor.Current = Cursors.Default;

            if (result != BSSDK.BS_SUCCESS)
            {
                MessageBox.Show("Cannot read the card", "Error");
                return;
            }

            userCardID.Text   = card_id.ToString("X");
            cardCustomID.Text = custom_id.ToString();
        }