/**
  * Validate the form
  *
  * @return  void
  */
 private function validateForm()
 {
     // is the form submitted?
     if ($this->frm->isSubmitted()) {
         // cleanup the submitted fields, ignore fields that were added by hackers
         $this->frm->cleanupFields();
         // validate fields
         $this->frm->getField('title')->isFilled(BL::err('TitleIsRequired'));
         $this->meta->validate();
         // no errors?
         if ($this->frm->isCorrect()) {
             // build item
             $item['id'] = $this->id;
             $item['meta_id'] = $this->meta->save(true);
             $item['title'] = $this->frm->getField('title')->getValue();
             $item['language'] = BL::getWorkingLanguage();
             // update the item
             BackendSlideshowModel::updateCategory($item);
             // trigger event
             BackendModel::triggerEvent($this->getModule(), 'after_edite_category', array('item' => $item));
             // everything is saved, so redirect to the overview
             $this->redirect(BackendModel::createURLForAction('Categories') . '&report=edited-category&var=' . urlencode($item['title']) . '&highlight=' . $item['id']);
         }
     }
 }