A friend of mine gave me a Nextel i830 phone. The phone is disconnected and has not been used but the phone is locked. I guess I have the wrong definition to unlocking a phone, but is there a certain code to type in? It also asks for the security code. The unlock code is 4 digits but the security code is I think 5 or 6. So is there a universal unlock code, or do i need to take it to the store?