A method of locating people by using radio frequency identification andor global positioning system that is imbedded in a gift card andor keytag which holds digital information in a microchip which communicates through a data base assigned for this use to locate missing or lost people when activated. According to the invention, the liquid supply to the detergent additive stored in the compartment is effected in dependency of the program sequence, wherein in particular the liquid supply to the compartment is repeated at different times. A set of data items in the first format are received by the service provider and analyzed according to the validation rules.