Unless you have set a code yourself, it is usually the last four digits of your cell number. If that doesn't work, try 1234 or the last 4 digits of the primary account holder's SSN.
this has happened to me before when you accidentally lock your phone and you cant make calls or get to the menu and dont know the code. There is no way to unlock it but to take it to the verizon store, Its such a pain.
take the battery ou, behind the battery on the phone is the code or "key" to unlock it
sometimes it is 0000
or
the last 4 digits of your phone number or the last 4 digits of numer of the person you bought it from if bought used...
certain phones use 1234