private void btnCloseSerial2_Click(object sender, EventArgs e)
 {
     mf.CloseGPS2Port();
     if (mf.spGPS2.IsOpen)
     {
         cboxBaud2.Enabled       = false;
         cboxPort2.Enabled       = false;
         btnCloseSerial2.Enabled = true;
         btnOpenSerial2.Enabled  = false;
     }
     else
     {
         cboxBaud2.Enabled       = true;
         cboxPort2.Enabled       = true;
         btnCloseSerial2.Enabled = false;
         btnOpenSerial2.Enabled  = true;
     }
 }