SIM Card Problem..Did I screw up? I need help/advice

[BaronvdB]

Ok so here's my problem:

Tonight I went to the AT&T store to by a "Go Phone" because I'm going to sell my current 16gb iPhone. The AT&T guy moved my account/number to the SIM that came with the Go Phone (I didn't realize that I probably could've just taken the SIM out of my iphone and put in the Go Phone until after the fact).

Anyway, I want to continue using my iPhone until I sell it but when i put the SIM from the Go Phone in my iPhone it doesn't work (it just says the call failed as soon as i hit the call button)...Do iPhone SIMs work with Go Phones but not the other way around?? The original SIM that's in my iPhone was deactivated when the AT&T moved my info the Go Phone SIM.

What should I do?

 

[BaronvdB]

Ok so here's my problem:

Tonight I went to the AT&T store to by a "Go Phone" because I'm going to sell my current 16gb iPhone. The AT&T guy moved my account/number to the SIM that came with the Go Phone (I didn't realize that I probably could've just taken the SIM out of my iphone and put in the Go Phone until after the fact).

Anyway, I want to continue using my iPhone until I sell it but when i put the SIM from the Go Phone in my iPhone it doesn't work (it just says the call failed as soon as i hit the call button)...Do iPhone SIMs work with Go Phones but not the other way around?? The original SIM that's in my iPhone was deactivated when the AT&T moved my info the Go Phone SIM.

What should I do?

I went back to AT&T today....they just gave me a new SIM card and told me to reactivate my iphone through itunes...I did that (had to call to get an "authorization" from AT&T...now I'm back using my iPhone and the SIM also works in the go phone so I'm good to go.

One last question..IF i sell my iPhone (I have a $375 offer standing right now) can i just pop the SIM in my go phone until I get the 3G iphone and then just pop the SIM into the 3G iphone?? Will that work?