I am trying to clear the memory on my LG CU500 phone, but its asking for a password. What should I do?

i don't remember setting one, is there like a universal password, or maybe a work around?I am trying to clear the memory on my LG CU500 phone, but its asking for a password. What should I do?
It's one of the following:





0000


000000


00000000


1234I am trying to clear the memory on my LG CU500 phone, but its asking for a password. What should I do?
If its verizon its normally the last 4 digets of your cell number