private void btnEditSelected_Click(object sender, EventArgs e)
        {
            if (lbCameras.SelectedIndices.Count != 1)
            {
                return;
            }
            editingIndex = lbCameras.SelectedIndex;
            CameraDefinition selectedCamera = (CameraDefinition)lbCameras.SelectedItem;

            if (selectedCamera != null)
            {
                AddCameraForm f = new AddCameraForm();
                f.ConvertIntoEditForm(selectedCamera);
                f.FormClosed += F_FormClosed_Edit;
                f.ShowDialog(this);
            }
        }