Help with webcam

I have a late 2010 model of MBA and for some reason I can't take pictures or record videos. When I bring up image capture it says no camera is connected. For some reason I don't have photo booth or isight in my apps folder or anywhere. I feel like I may have deleted them, so is there any possible way to get them back or get any app or software that I can download so I can use the camera for skype? I dont have a disk drive that I can use, but my roommate does have a macbook with photobooth and isight if that helps at all. Thanks