Cannot sign in to my iTunes account, and therefore cannot use app store or itunes.

First I was just trying to open the app store to update my apps. When I tred opening the app store it said, "Cannot connect to itunes store." The same thing popped up when I tried to open iTunes. So I went to my settings and tried to sign out and sign in to my Apple account. When I tried to sign in again it said, "Cannot connect to iTunes store," again. I have read the following articles and tried all possible solutions to no avail:

• http://support.apple.com/kb/TS1368
• http://support.apple.com/kb/ts1398
• http://support.apple.com/kb/TS1559

Once again, none of these provided any solution to me after taking all suggested action. Any help would be greatly appreciated. Thank you in advance.