I have a mid 2012 MacBook pro running OS X Lion 10.7.5. I recently bought the AppleTV so that I could view my laptop on my TV. I have managed to get a connection and the TV can find my movies, photos etc. However I can't find an Airplay icon or how to enable it. I only have the standard TV icon. How do I find the airplay icon and more importantly how do I get my laptop to show on my TV. Any help would be appreciated.