PROGRAMMING CHALLENGE: Create a graveyard scene where a ghost appears and flies across the screen. Constraints: 1. When the gravestone is clicked, a ghost arises from the grave, gets bigger, and flies off the screen. 2. The ghost should increase in size as it flies across the screen. 3. When the ghost appears, a scream sound should be played. 4. When the animation is completed, it should be able to be restarted by clicking on the gravestone. *VERY DIFFICULT* EXTENSION CHALLENGE: Once the animation has started, additional clicks on the gravestone don't affect it until it's finished.