Can't choose Carrier manual - AT&T iPhone

[mst90]

I can't choose my carrier manual on my AT&T iPHone 4 (iOS4.1-jb).
Is there any way to see carriers etc? Maybe a Jailbreak app?

 

[Applejuiced]

Is it JB and unlocked?
What do you mean choose carrier manual?

 

[mst90]

Is it JB and unlocked?
What do you mean choose carrier manual?

Only JBked

I want to choose my carrier manually, because im in a extended area,but there is no option.

 

[Applejuiced]

Oh I see. So you dont get any roaming charges.
Im not sure if we have that option.
I know you can disable data roaming but not actual roaming calls or messages.