Motorola SLVR L7

I just purchased a handsfree earpiece to use with my SLVR. The only thing I realized may be a problem is that I can't lock the keypad during a call. I would like to be able to connect to the headset then put the phone in my pocket for the rest of the call, but without the keypad being locked I would be afraid of pressing buttons or accidentally hanging up.

Does anyone know if it is possible to lock the keypad while connected to a call via a handsfree bluetooth connection?