Phiet69 need helps to program a remote transmitter

Hi there,
I just bought a used Honda Accord 1997 which equiped with the Chapman security system with keyless entry system installed. But the car does not have any remote transmitter. So I tried the procedures steps listed below to re-program a remote transmitter for my car, somehow the system can learn the remote transmitter, but look like it does not save the new transmitter code in memory. Here is the procedure I did:

1) Open the driver's door.
2) Turn vehicle ignition on.
3) Press and hold the emergency override button.
After 15 seconds, the siren or horn will sound three (3) times. This indicates that the unit has entered the tranmitter programming mode.
4) Release the button.
5) Press the #1 (lock) or ARM button on the remote transmitter to be programmed. The siren or horn will sound once, indicating that the system has "learned" that remote transmitter.
6) Turn the vehicle ignition off to exit the programming mode.

But the problem is that when I Turn the vehicle ignition off or close the driver's door, the system does not respond to the remote transmitter any more. Note that the system responded to the remote transmitter while it is in programming/learn mode.

Thanks in advanced and appreciate for any help !
Phiet69