before my brother got a new phone, he gave the iphone 3gs to me. So i was going to use iphone and throw away my old cell phone. Now i tried to plug it in to my laptop and when my itune pop up, it said "The sim card inserted in this iphone does not appear to be supported" even though i had my old cell phone sim card on the iphone

Does this mean, I can't use it?
Can anyone one help me?

THANKS IN ADVANCE!!