function updateCMSFields(FieldSet &$fields)
 {
     if (!FlashObject::has_external_flash_file()) {
         $show = true;
         if (is_array(self::get_classes_with_flash()) && count(self::get_classes_with_flash())) {
             if (!in_array($this->owner->ClassName, self::get_classes_with_flash())) {
                 $show = false;
             }
         }
         if (is_array(self::get_classes_without_flash()) && count(self::get_classes_without_flash())) {
             if (in_array($this->owner->ClassName, self::get_classes_without_flash())) {
                 $show = false;
             }
         }
         if ($show) {
             $fields->addFieldToTab("Root.Content.FlashObject", new FileIFrameField('FlashFile', 'File'));
             $fields->addFieldToTab("Root.Content.FlashObject", new TextField('Title', 'Title'));
         }
     }
     return $fields;
 }