SIM card problem?

[YeMan]

So yesterday during school I took my phone out of my pocket and noticed on my Nokia Lumia 900, the sim card was sticking out.... So I pushed it in and tried to send a text, and it said something like "SIM is not in or damaged" and it was in... I took it out and put it back in a few times but it still doesn't work. Any fixes at home? Or should I go to my AT&T store? And will I need a new phone or just SIM card?

 

[Schnuffi]

I would go to the store and hope the sim card is damaged and not the phone.