Cant make any phone calls...please help


Cant make any phone calls...please help
when i go to the phone i cannot pick a contact, edit a contact, dial a number, basically i cant use any phone features. nothing. i cant use favorites, recents, keypad, or voicemail, the only thing i can do is scroll my contacts, and go back home. everything else on the "phone" works fine, except for this pretty important feature. i can answer calls, but not make them. my "phone" is only been out the box barely 24 hours and this already happened...anybody help?
I just had the same problem. The way I resolved it was by holding the button on the top down for several seconds. You are then prompted to "slide to power off". Power it off, and then press the button on the top again to restart your iphone. I was then able to use all of the phone functions again.
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