An example of using broadcast and receive. Scratchy's friends want to surprise him on his birthday. They are all hiding in his room. Scratchy enters his room with his friend Alex. Alex says "Surprise!" All the friends jump out and shout "Happy Birthday!" The way this works is that Alex also broadcasts a hidden message "StopHiding" (besides saying "Surprise!" on the screen). We program the friends (two other sprites) to show themselves when they receive the "StopHiding" message, and to say Happy Birthday!
