2. The method according to claim 1 , wherein the first user interface mechanism and the second user interface mechanism are different user interface mechanisms.
3. The method according to claim 2 , further comprising: changing a state of the first user interface mechanism in response to the activation of the first user interface mechanism; changing a state of the second user interface mechanism in response to the activation of the first user interface mechanism; changing the state of the first user interface mechanism in response to the activation of the second user interface mechanism; changing the state of the second user interface mechanism in response to the activation of the second user interface mechanism.