Lubek Jastrzebski and Nancy Nemhauser, of Mount Dora, Fla., noticed their autistic son, Chip, kept opening the same art book and turning to the same page: Van Gogh's "The Starry Night." They were inspired to paint a mural on their house based on the masterpiece. But could a city housing ordinance against graffiti defeat such ambitious artistic expression? Steve Hartman reports.