ehhh, why do you want to do that? this will make the footwell lights be on ALL the time if the parking lights are on.
i've done this two different ways: (one is simpler and the other is a bit more complex but safer.)
the former involves pulling out your dome light and wiring the 12v+ lead to the yellow wire. i think there are two or three but either one should do the trick. then you just ground the footwell lights near wherever they lay. this also makes them fade with the dome light.
the latter involves a relay and the door trigger. i'll just link you to my write up instead of repeating myself:
WRITE-UP: Footwell courtesy lights