A method (500), a handheld electronic device (102) and an external accessory (402) for controlling at least one function of a plurality of functions of the handheld electronic device is provided. The method includes determining (504) whether the handheld electronic device is docked in an external accessory. Further, the method includes measuring (506) a first magnetic field density when the handheld electronic device is docked in the external accessory. Furthermore, the method includes generating (508) a signal to activate at least one function, based on an electrical parameter.