private void button2_Click(object sender, EventArgs e)
 {
     if(_SettingsDialog != null)
         _SettingsDialog.Close();
     _SettingsDialog = new SettingsDialog();
     _SettingsDialog.OnSettingsChangedEvent += OnSettingsChanged;
     _SettingsDialog.ShowDialog(this);
 }
        void MainViewer_FormClosed(object sender, FormClosedEventArgs e)
        {
            if(_SettingsDialog != null)
                _SettingsDialog.Close();
            _SettingsDialog = null;
            if(_AdminLogin != null)
                _AdminLogin.Close();
            _AdminLogin = null;


            StopTrafficTimer();

            foreach(var item in _FileDownloadControls)
                item.Running = false;
            _FileDownloadControls.Clear();
            if(_Client != IntPtr.Zero)
                Destroy_Client(_Client);
            _Client = IntPtr.Zero;
            viewPort1.OnDraw_CB = null;
            Application.RemoveMessageFilter(_InputListener);
        }