2000 astro keyless entry

can anyone give me the codes to reprogram my keyless entry,I put a new battery in it and it still won't work, any help would be appricated

1. With the driver door closed and ignition OFF, hold down the power unlock button on the door panel.

2. Turn the ignition switch to the ON position.
Turn the ignition switch to the OFF position.
Turn the ignition switch to the ON position.
Turn the ignition switch to the OFF position.

3. Release the power unlock button on the door panel. The remote control door lock receiver module should respond by locking the doors, then unlocking the doors to indicate that the receiver is in the programming mode.

Important: All transmitters must be programmed at this time. When a new transmitter is programmed, it will deactivate any old transmitter programming.

4. Hold down both the lock and unlock buttons on the transmitter until the remote control door lock receiver responds in the following manner:
Locking the doors.
Unlocking the doors.

5. Repeat step 4 for each additional transmitter.

6. Turn the ignition switch to the ON position in order to exit the transmitter programming mode.

Instructions for this and many other remote keyless entry systems programming can be found at http://www.programyourremote.com/