I was wondering, does anyone know how to program a remote entry (original still), for the '99 alero??

From a '99 Alero Owners Manual............
To resynchronize your keyless remote:
1. Stand close to the vehicle
2. Press and hold the LOCK and UNLOCK buttons on the transmitter at the same time.
3. Hold the buttons for five seconds. In this time the doors should lock and unlock once. This confirms the resynchronization.

Hope this helps...Good luck!

thanks much.. worked great.