I watched this movie in the early 90s but can't remember the name. All I know is that the half brother is madly in love w/ his half sister and goes crazy over her. She doesn't love him but is worried about her mentally challenged sister who lives in a home. Does anyone know about this movie?

I'm trying to find the name of this movie also please update if u find out as I will do the same.. thanks

the movie name is "CLUELESS" starring Alicia Silverstone.
you can order the dvd at:

http://www.amazon.com/gp/product/B0009W5IP6?ie=UTF8&tag=spirpub-20&linkCode=as2&camp=1789&creative=9325&creativeASIN=B0009W5IP6