Unroll pizza dough and press onto the bottom and 1/2 inches up the sides of a greased 15-inch by 10-inch by 1-inch baking pan. Bake at 425° for 8-10 minutes or until golden brown. Using a 1-inch star cookie cutter, cut eight stars from the American cheese. Cut each strip of string cheese in half lengthwise. Spread pizza sauce over crust. Arrange stars in the upper left corner. For stripes, arrange 15 pieces of string cheese over sauce (save remaining piece for another use). Bake 5-8 minutes longer or until cheese is melted.