Sometimes they need to be recoded if the battery has been flat for a while. Try this..
start with drivers door open, key out of ignition.
Key in, key out two times.
Close open door two times.
Key in, out 1time.
Close, open door two times
key in, close door, key on, key off,
key out, push both buttons for 3 secs, push one button for 3 secs.
Doors should lock/unlock.