Looking for a movie that is about an evil lady and she is at a party, she has sex with guys and it sucks the life out of them.I remember at the end of the movie she takes of as a red light into the sky

Can you think of any more details at all?

In the movie I think she is posing as a school student and she goes to a party and that's where she gets the guys, there is also a guy in it who is trying to stop her. There is not much more I remember I was only young when I watched it.

Sounds something like " Lifeforce" 1985. But the girl is found in outer psace and is original vampire. She is found on comet.
Hope this one works for you

LOL! rhbell, I remember Lifeforce! I hate to admit I sat in the theatre laughing while watching it.

smo85, although this wasn't from the 80's what you are describing sounds a lot like Species, click on the link Species (1995) (http://www.imdb.com/title/tt0114508/)