yup ... just did that myself so had the answer for ya but darn got to it before i could tip ya.
best way to find out in future, 5 dollar test light from any auto place. turn on the headlight switch and attach the clip to ground and use test light probe to check each bulb socket pin. the one that lights is positive.

PS ... lantana from your previous posts i know you know this but for people newer to the hobby thought i'd put it there for them.