The present invention relates to a method and an arrangement for determining the function of a press-button switch. A press-button switch (3; 31,32, . . . , 3N) has been arranged in a peripheral (2) connected detachably to a mobile-phone (1). According to the method, a press-button switch (e.g....http://www.google.de/patents/US5819175?utm_source=gb-gplus-sharePatent US5819175 - Method and assembly for assigning a function of an electronic device