LG 840G User Manual page 72

Security
Phone lock: You can use a security code to avoid unauthorized use of
the phone lock to Lock Phone Now, your phone will lock immediately.
Change Codes:
current password to a new one. You must enter the current password
before you can specify a new one. You can change the Security Code.
Memory
Used Space:
Set Storage Default:
various types of features.
Reset Settings
the security code.
Master Reset:
Master Clear:
LG 840G | User Guide
When Power On, the phone will