2000 impala keyless entry dosnt work

I have a 2000 impala with 20k miles. Keyless entry buttons do not open door but the red PANIC button does work very will. What im i doing wrong? Did i diable it by accident?????? How do i re-acivate it??

try reprogramming them... when you reprogram one you have to reprogram all.

FOB PROG (Remote Keyless Entry Transmitter Programming): This feature allows you to match the remote keyless entry transmitter to your vehicle.
To match the transmitter:

1. Scroll, using the SEEK up or down arrows, until FOB PROG appears on the display.
2. Press the PREV or NEXT button to enter the submenu. The current selection will have an asterisk next to it. BEGIN will be displayed.
3. Press the DISP button to start programming. When the message PUSH FOG flashes, press and hold the LOCK and UNLOCK buttons on the first transmitter at the same time for 15 seconds. A chime will be heard to verify the transmitter is learned.
4. Repeat Step 3 for each additional transmitter.

The mode you selected is now set. You can either exit the programming mode by following the instructions later in this section or program the next feature available on your vehicle.

EXIT (Exit Feature Customization Mode): This feature allows you to exit the vehicle customization programming.
To Exit:
1. Scroll until EXIT appears on the display.
2. Press the DISP button to exit programming. A chime will he heard to verify the exit.