public function actionCreate()
 {
     $nParentId = Yii::app()->request->getParam('parent', 0);
     $nPositionId = Yii::app()->request->getParam('position', NULL);
     $sName = Yii::app()->request->getParam('name', 'New node');
     $nItemId = Item::treeCreate($nParentId, $nPositionId, $sName);
     if ($nItemId) {
         $this->jsonOutput(['id' => $nItemId]);
     }
     $this->jsonOutput(['message' => 'Cannot add item.'], 'error');
 }