CNCGUI.MainForm.StartBtn_Click C# (CSharp) Method

        private void StartBtn_Click(object sender, EventArgs e)
        {
            int baud = 0;
            if (PortSpeed.SelectedItem == null)
            {
                MessageBox.Show("Baudrate not select", "Error");
            }
            else if (!int.TryParse(PortSpeed.SelectedItem.ToString(), out baud))
            {
                MessageBox.Show("Invalid baudrate", "Error");
            }
            else if (PortsList.SelectedItem == null)
            {
                MessageBox.Show("Port not select", "Error");
            }
            else
            {
                serialPort.PortName = PortsList.SelectedItem.ToString();
                serialPort.DataBits = 8;
                serialPort.StopBits = StopBits.One;
                serialPort.Handshake = Handshake.None;
                serialPort.Parity = Parity.None;
                serialPort.BaudRate = baud;
                try
                {
                    serialPort.Open();
                    if (serialPort.IsOpen)
                    {
                        setPortOpenControls();

                        if (SendCommand("\n") == E_RESPONSE.E_OK
                        && SendCommand("$ic=0\r\n") == E_RESPONSE.E_OK
                        && SendCommand("$ej=0") == E_RESPONSE.E_OK
                        && SendCommand("$ee=0") == E_RESPONSE.E_OK
                        && SendCommand("$ec=0") == E_RESPONSE.E_OK
                        && SendCommand("$ex=0") == E_RESPONSE.E_OK
                            )
                        {
                            Set_mm_Btn_Click(sender, e);
                        }
                    }
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message, "Error");
                    setPortCloseControls();
                    if (serialPort.IsOpen)
                        serialPort.Close();
                }
            }
        }