How can I sign out of my iTunes account on the iPhone?

Signing out of your iTunes account on the iPhone is simple. Follow these steps to log out:

1. Navigate to Settings -> Store
2. Touch the Sign Out button

You are now logged out of your iTunes account on the iPhone. To sign in:

1. Navigate to Settings -> Store
2. Touch the Sign In button
3. Enter the email address and password associated with your iTunes account.

I have taken my Iphone from usa to Iran but its hi-fi did not work, so i followed up the instruction for setting.
When it was done my iphone is locked by sign of iTune and a usb picture.
What i can do is only to get sos calls, and it woulnt give me any other options.
Pls hel if possibl, and let me khow how can i get out of this jamed page.
Thanks Fred

Your problem is simple. It sounds like a passcode lock if you swipe. Otherwise it sounds like a possible wrong country for USA tech. Its like a DVD if you watch movies. Not all are licensed to all countries. You need to talk to a local phone dealer. Maybe they can unlock it or trade it for one that will work in your country.

Dear Sir,
I need to update some programs from my ITunes Store in my iphone but a box shows up asking me to enter an email address's password of which I don't know,so I tried to change it from settings app and I signed in my Apple ID from setting app ,and still that email address which I don't know it's password shows up before downloading any new updates from iTunes Store. I need to mention I updated my iOS recently and I'm running iOS 7.1 now. Would you please help me in fixing up this problem? Thanks.