Can I make my AT&T iphone 4s work on Virgin Mobile?

I have someone who says they can unlock and flash the iphone 4S to Virgin Mobile. Is this possible?

Flashing can be done using the software… I would suggest the Remote Unlock service to Unlock I-phone 4 from AT&T NETWORK… Visit the site http://www.theunlockarena.com/apple-iphone-4/rs13wp9/ get remote unlock service and unlock it easily… Then Use with Virgin GSM Network… Virgin available in CDMA Network… But CDMA Network can't be used in Unlocked Phone.

No it is not possible.

Check this out
http://www.vunlock.com/
i'm not completely sure but they claim so