You
can set the keypad of your phone to lock automatically
after a pre-set time delay. You can set the delay time
from 10 seconds up to 59 minutes 59 seconds and when the
time is up, the keypad locks automatically, preventing
accidental key presses.
Press Menu, and select Settings, Phone settings
and Automatic keyguard.
To activate the automatic keyguard, select On
and the phone displays Set delay:. Key in the
time and press OK.