MissionPlanner.SerialOutputNMEA.BUT_connect_Click C# (CSharp) Method

        private void BUT_connect_Click(object sender, EventArgs e)
        {
            if (comPort.IsOpen)
            {
                threadrun = false;
                comPort.Close();
                BUT_connect.Text = Strings.Connect;
            }
            else
            {
                try
                {
                    comPort.PortName = CMB_serialport.Text;
                }
                catch
                {
                    CustomMessageBox.Show(Strings.InvalidPortName);
                    return;
                }
                try
                {
                    comPort.BaudRate = int.Parse(CMB_baudrate.Text);
                }
                catch
                {
                    CustomMessageBox.Show(Strings.InvalidBaudRate);
                    return;
                }
                try
                {
                    comPort.Open();
                }
                catch
                {
                    CustomMessageBox.Show("Error Connecting\nif using com0com please rename the ports to COM??");
                    return;
                }

                t12 = new System.Threading.Thread(new System.Threading.ThreadStart(mainloop))
                {
                    IsBackground = true,
                    Name = "Nmea output"
                };
                t12.Start();
            }
        }