Can I upgrade to an iPhone 5? - 1

I'm with AT&T and I currently have the iPhone 4. I got it last year in October when I signed up for a 2 year contract. They were having a deal where you could get the 4 for $1.00 if you signed up for a contract.So, I ended up getting it for a buck. My question is, can I now upgrade to an iPhone 5? Will I have to pay the difference. If so, how much?

Ask them bro i guess you should be able to do it but no harm in asking right?