PROGRAMMING CHALLENGE: Create a day time scene where a butterfly appears and flies across the screen. Constraints: 1. When the tree is clicked, a butterfly arises from behind the tree, moves toward the right, gets bigger, and flies off the screen. 2. The butterfly should increase in size as it flies across the screen. 3. When the butterfly appears, a magic spell sound should play. 4. When the animation is completed, it should be able to be restarted by clicking on the tree. *VERY DIFFICULT* EXTENSION CHALLENGE: Once the animation has started, additional clicks on the tree don't affect it until it's finished.
