Samsung SGH-D500 Manual page 186

Settings
Phone lock
(Menu 9.7.3)
When the Phone Lock feature is enabled, the phone is
locked and you must enter a 4- to 8-digit phone
password each time the phone is switched on.
The password is preset to "00000000" at the factory. To
change the phone password, see the Change password
menu (Menu 9.7.4).
Once the correct password has been entered, you can
use the phone until you switch it off.
The following options are available:
Disable: you are not asked to enter the phone password
when you switch on the phone.
Enable: you are required to enter the phone password
when you switch on the phone.
Change password
(Menu 9.7.4)
The Change Password feature allows you to change your
current phone password to a new one. You must enter
the current password before you can specify a new one.
The password is preset to "00000000" at the factory.
Once you have entered a new password, you are asked
to confirm it by entering it again.
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