HT4232: Apple ID: Security and your Apple IDLearn about Apple ID: Security and your Apple ID
Currently Being ModeratedSep 20, 2013 11:02 AM (in response to joycefromscranton)
Only you would know it. 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. At this point, you will lose all data on the phone.
See this for more info... http://support.apple.com/kb/HT1212