/**
  * Delete an existing model if no phone uses the model.
  */
 public function delete($id)
 {
     $astPhonesWithModel = astPhoneModel::where('PHONE_MODEL_ID', '=', $id)->get();
     if (count($astPhonesWithModel) == 0) {
         $astPhoneModel = astPhoneModelModel::findOrFail($id);
         $astPhoneModel->delete();
         Session::flash('astMessage', 'Model has been deleted!');
         return Redirect::route('models');
     } else {
         Session::flash('astDeleteMessage', 'In order to delete this model, all phones with this model must be deleted first.');
         return redirect()->route('showModel', [$id]);
     }
 }