HT4113: iOS: Using passcodesLearn about iOS: Using passcodes
Currently Being ModeratedSep 9, 2013 6:16 AM (in response to shahrozcheema)
If you forgot (or don't know) your passcode, restore the device from backup on the last computer it was synced with when the passcode was turned on... this will remove the passcode. If you do not have access to the last computer it was synced with, or you don't have a backup, you will have to force it into recovery mode & restore as a new device.
See this for more info... http://support.apple.com/kb/HT1212