Saved this information from awhile ago, hope it helps. It should also be listed in your manual.
1. using the key , lock your doors manually to set the alarm, .
then unlock the car get in and close the door
2. Insert key in ignition.Turn to position 1 and quickly turn back off . Remove the key
3.At same time you are holding unlock button on the key, press the lock button three times in sucession, You should hear the doors lock and unlock,
4. Quickly (with in 30 seconds pick up the other keyand pres the buttons as above,Do not put the second key in the ignition. try it and see, hope it works,.