Who is the girl in the pink top at the house party?

Does anybody know who the actress is that appears at the house party just after the 3 characters walk into the house? She has a tight pink spaghetti strap top, dark (almost black) tight skirt on and she's holding a red cup. I have tried looking for her name on DVD's and nothing. I wish this sight could get the names of all people in the movies because I find that more often not, I see an actor or actress in a movie and cant find their names because they are not listed anywhere. I was under the impression that all actors had to be credited but maybe I am wrong. I did like this movie a lot. if anybody could help me find the name I would really appreciate it.