How do I lighten my compter screen?

I play quicktime trailers but they are very dark. Is there anyway I can lighten the tone or is it just the type of screen I have?

*facedesk*

There are buttons on the front of your screen, are there not?

This is really, really painful to read.

How long have you had a computer? >.<;;

Have you tried to reset the contrast on the Quicktime player?

No...how?