/**
  * Delete files
  *
  * @access public
  * @param
  * 
  */
 public function deleteFiles()
 {
     if (!isset($_POST['file_id'])) {
         ilUtil::sendFailure($this->lng->txt('select_one'));
         $this->editFiles();
         return false;
     }
     include_once 'Services/AdvancedMetaData/classes/class.ilAdvancedMDRecordExportFiles.php';
     $files = new ilAdvancedMDRecordExportFiles();
     foreach ($_POST['file_id'] as $file_id) {
         $files->deleteByFileId((int) $file_id);
     }
     ilUtil::sendSuccess($this->lng->txt('md_adv_deleted_files'));
     $this->showFiles();
 }