Forgot my password and master password and I'm locked out my mac book

Customer forgot password
If the customer forgot the password for the computer:
1. Insert the Software Install and Restore DVD.
2. Restart the computer while holding down the C key on the keyboard.
3. When the installer appears, chose Reset Password from the Installer menu
4. Follow the on-screen instructions.


Here is the link to the user manual and below that is the factory service manual...

http://manuals.info.apple.com/en_US/PowerBookG4_15inch1GHz-867MHzGettingStarted.PDF

http://tim.id.au/laptops/apple/PowerBook%20G4%20(15-inch%20FW800).pdf

To reset the administrator password using the Mac OS X disc:

1. Insert the Mac OS X Install disc and restart the computer.
2. When you hear the startup tone, hold down the C key until you see the spinning gear.
3. When the Installer appears, choose Utilities > Reset Password.
4. Follow the onscreen instructions to change the password.
5. Quit the Installer and restart your computer while holding down the mouse button to eject the disc.