I have an T-mobile phone & Sim. Whats the code so i can use it in At&T phone?

[ChrisParedes]

I had an T-mobile blackberry phone and my "A" button broke. So i got my friends At&T Blackberry Phone,and i called costumer service for the code.But today i took off the sim card and it dosen't let me use the At&T phone nor the T-mobile. Does anyone know what i can do?

[Unregistered]

If you want to unlock your Blackberry mobile phone from the network lock,I would suggest you to get an unlock code from Unlocking4u.com at reasonable price and unlock it using the unlocking instructions given for your mobile phone from that site itself.