Ok I got the Iphone 5 and facing problems with Imessage and Facetime.

hi Everyone...

I just got the Iphone 5, and i am not able to use Facetime nor Imessages. I receive Imessages from friends, and can reply to them, but i cant start the conversation with them..... i tried restarting the phone, changing settings and restrictions but nothin is working.

Facetime is no where to be found, i tried using Siri to make a facetime call, and she said i need to set a facetime account, and i cant find it...

Knowing that i am using both services on my Ipad and it works fine.

appreciate your help !!