Nokia 6131 security code problem. Please help!

I've had this phone for acouple months now. it's never asked for a security code before though. i went to turn my phone on today and i can't get to anything on my phone b/c i have to enter a security code and i have no idea what that code be.
i've done some researching (lol) and i know it's not the old 12345 and i even tried a master code that i think is right for my phone. but i dont know if i'm using the master code right in the first place.
can anyone tell me how i can get into my phone please?!
Thanks!

the big problem is i can't get into my phone! ah please please help