There are some issues with your squat, but we really can't give you a full form check evaluation based on that video. Read the sticky from the technique forum (http://startingstrength.com/resource...ad.php?t=20249) about filming form checks, and get some proper footage of your squats, so we can give you helpful advice.
From this video, I can see that you have a bunch of knee slide at the bottom, but I'm going to refrain from commenting until I see good footage of the whole squat.