Prom Night Review

I recently saw this movie and you knew what was going to happen for atleast the first hour. By the way, the movies only about an hour and a half long.  It's about a girl whose parents get killed by her stalker.  He is released from jail and ends up killing people, her friends.  I'm not giving anything away there, that's where it was predictable.  I have a few questions.  What girls go anywhere alone, especially on prom night at a hotel they have never been to?  If your girlfriend sees something why let her go alone?  I think this movie is not what is was thought to be.  Don't get me wrong it was decent.  It was just very predictable, but the last half hour was pretty good.