public function IncludeMap($objectclass)
	{
		try
		{
			Includer::RequireClass($objectclass,"Model/DAO/");
		}
		catch (IncludeException $ex)
		{
			throw new Exception($ex->getMessage() . '.  If a map file does not exist then ' . get_class($this) . ' can implement GetFieldFromProp instead.');
		}
	}