I'm trying to find the tittle of a movie I saw a long time ago but I don't remember any name of actors. It's about a teenage girl that drowns in a swimming pool wile her boyfriend who was drugged couldn't help her (he was drugged by another girl who was in love with him) and then she comes back to earth as a ghost to show that she didn't die by accident. She can also merge with another body en control it and I think at the end she definitely takes the body of another girl who wants to be with er grandfather.
Does somebody knows it?
Thanks!

Dying to Live (http://www.imdb.com/title/tt0194835/)