iphone 4s sim swap for straight talk

i had gotten my iphone 4s about a month ago and a friend of mine unlocked it for me.i have been trying to do a sim swap with my iphone 4s but its not letting me go into cellular data for some reason. i take my straight talk sim card out and put in the t-mobile one(unactivated). i go to settings, general, and cellular and than i take the t-mobile sim card put in the straight talk sim card but it doesnt stay on that page. it goes right back to the general page. i restored my phone twice now and i still cant get it to work. please someone help me out.

thanks in advance
alizabeth

Once you've had an iPhone unlocked you put the new sim card in, connect it to iTunes and it will activate.

Once that's done you'll be fine

What happens with the tmobile sim in?

Nothing will happen with the T-Mobile sim card inserted unless it's been activated by T-Mobile. Her post states she used an unactivated T-Mobile sim. She was apparently trying to "fool" the system but it didn't work.

Dysfunction said:

What happens with the tmobile sim in?

Click to expand...

when i put the t-mobile sim card in it goes right back to the general menu.

You prob need to flash the phone itself to straight talk server/carrier. Once that is done it should work. And also is the phone GSM or CDMA?? if GSM then should work anyways but if CDMA then you might need to flash it like i said earlier...

Here is link to possibly tell difference.
Differences Between iPhone 4 AT&T/GSM & iPhone 4 Verizon/Sprint/CDMA @ EveryiPhone.com