private void cmdRead_Click(object sender, EventArgs e)
        {
            bool bRet;
            int  vErrorCode = 0;

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

            bRet = bpc.EnableDevice(Program.gMachineNumber, 0); // 0 : disable

            if (!bRet)
            {
                lblMessage.Text = util.gstrNoDevice;
                return;
            }

            GCHandle gh = GCHandle.Alloc(unlockGroupInfo, GCHandleType.Pinned);
            IntPtr   AddrOfunlockGroupInfo = gh.AddrOfPinnedObject();
            int      nAddr = AddrOfunlockGroupInfo.ToInt32();

            bRet = bpc.GetDeviceLongInfo(Program.gMachineNumber, 7, ref nAddr);

            if (bRet)
            {
                lblMessage.Text = "Success!";
            }
            else
            {
                bpc.GetLastError(ref vErrorCode);
                lblMessage.Text = util.ErrorPrint(vErrorCode);
            }

            bRet = bpc.EnableDevice(Program.gMachineNumber, 1); // 1 : enable
        }