protected function _createTreeManager( $siteid )
	{
		if( !isset( $this->_treeManagers[$siteid] ) )
		{
			$context = $this->_getContext();
			$config = $context->getConfig();
			$dbm = $context->getDatabaseManager();


			$treeConfig = array(
				'search' => $this->_searchConfig,
				'dbname' => $this->_getResourceName(),
				'sql' => array(
					'delete' => str_replace( ':siteid', $siteid, $config->get( 'mshop/catalog/manager/default/item/delete' ) ),
					'get' => str_replace( ':siteid', $siteid, $config->get( 'mshop/catalog/manager/default/item/get' ) ),
					'insert' => str_replace( ':siteid', $siteid, $config->get( 'mshop/catalog/manager/default/item/insert' ) ),
					'move-left' => str_replace( ':siteid', $siteid, $config->get( 'mshop/catalog/manager/default/item/move-left' ) ),
					'move-right' => str_replace( ':siteid', $siteid, $config->get( 'mshop/catalog/manager/default/item/move-right' ) ),
					'search' => str_replace( ':siteid', $siteid, $config->get( 'mshop/catalog/manager/default/item/search' ) ),
					'update' => str_replace( ':siteid', $siteid, $config->get( 'mshop/catalog/manager/default/item/update' ) ),
					'update-parentid' => str_replace( ':siteid', $siteid, $config->get( 'mshop/catalog/manager/default/item/update-parentid' ) ),
					'newid' => $config->get( 'mshop/catalog/manager/default/item/newid' ),
				),
			);

			$this->_treeManagers[$siteid] = MW_Tree_Factory::createManager( 'DBNestedSet', $treeConfig, $dbm );
		}

		return $this->_treeManagers[$siteid];
	}