I am looking for the name of a movie...from what i can remember about it some kids are in a cabin and they are?

i am looking for the name of a movie...from what i can remember about it some kids are in a cabin and they are talking about chanting something in the bathroom mirror and no one wanted to do it so one girl said she would (she has dark hair)so she goes in there and does it and when she comes out she says nothing happened but it did she was possessed.....thats all i can remember about.i sure hope somebody knows the name of this movie