private void cmdGetDeviceStaus_Click(object sender, EventArgs e)
        {
            int     vStatus;
            int     vValue     = 0;
            int     vErrorCode = 0;
            Boolean vRet;

            lblMessage.Text = "Working...";
            Application.DoEvents();

            vStatus = cmbSatus.SelectedIndex + 1;

            vRet = bpc.EnableDevice(Program.gMachineNumber, 0); // 0 : false
            if (!vRet)
            {
                lblMessage.Text = util.gstrNoDevice;
                return;
            }

            vRet = bpc.GetDeviceStatus(Program.gMachineNumber, vStatus, ref vValue);
            if (vRet)
            {
                switch (vStatus)
                {
                case 1:
                    lblMessage.Text = "(1) = Manager count = " + vValue;
                    break;

                case 2:
                    lblMessage.Text = "(2) = User count = " + vValue;
                    break;

                case 3:
                    lblMessage.Text = "(3) = Fp count = " + vValue;
                    break;

                case 4:
                    lblMessage.Text = "(4) = Password count = " + vValue;
                    break;

                case 5:
                    lblMessage.Text = "(5) = SLog count = " + vValue;
                    break;

                case 6:
                    lblMessage.Text = "(6) = GLog count = " + vValue;
                    break;

                case 7:
                    lblMessage.Text = "(7) = Card count = " + vValue;
                    break;

                case 8:
                    lblMessage.Text = "(8) = Alarm status = " + vValue;
                    break;
                }
            }
            else
            {
                bpc.GetLastError(ref vErrorCode);
                lblMessage.Text = util.ErrorPrint(vErrorCode);
            }

            bpc.EnableDevice(Program.gMachineNumber, 1); // 1 : true
        }