public function setCustomerId( $customerid )
	{
		if ( $customerid === $this->getCustomerId() ) { return; }

		$this->_notifyListeners( 'setCustomerId.before', $customerid );

		$this->_values['customerid'] = (string) $customerid;
		$this->_modified = true;

		$this->_notifyListeners( 'setCustomerId.after', $customerid );
	}