Lock the keys and touch screen
To lock or unlock the touch screen and the keys, slide the lock switch on the side of
the device.
When the touch screen and keys are locked, the touch screen is switched off and
the keys are inactive.
The screen and keys may be locked automatically after a period of inactivity. To
change settings for automatic screen and key locking, select Menu > Settings and
Phone > Phone mgmt. > Auto. keyguard > Keypad autolock period.