Choose one of the following options:
Turn key lock on or off, go to 1a.
Select setting for automatic key lock, go to 1b.

To turn on the key lock:
Briefly tap On/Off.

To turn off the key lock:
Briefly tap On/Off.

Drag the arrow right.

Tap Settings.

Tap General.

Tap Auto-Lock.

To turn on automatic key lock:
Tap the required interval.

To turn off automatic key lock:
Tap Never.

Tap the Home key to return to standby mode.