MacBook Air brightness problem

I got my MacBook Air about one month ago. today when I turned it on I went to turn the brightness of the screen down, since it was at the max. Normally, if you turn it down all the way, the screen goes black. but for me its turning black even if I turn it down by 1 bar ( by one bar I mean those little squares). Anyone know whats going on and how to fix it?

Try an NVRAM reset: