Locked Out, Forgot Lock or Restrictions Passcode, or Need to Restore Your Device
8. RecBoot: Easy Way to Put iPhone into Recovery Mode - if all else fails.
Forgotten Restrictions Passcode Help
If this method does not work, then you will need to fully Restore your
device as New
if you don't have a backup that doesn't contain a passcode, the only way to keep using the iPad is to restore it using http://support.apple.com/kb/ht1212 , but there's no Apple supported way to prevent losing your data. Passwords are made for security, that's why you should remember them.