def setup
  @rectX =  0
  @fr    = 30          #starting FPS
  background(200)
  frameRate(@fr)       # Attempt to refresh at starting FPS
  @clr = color(255, 0, 0)
end

def draw
  background(200)
  @rectX += 1          # Move Rectangle

  if @rectX >= width
    # If you go off screen.
    if @fr == 30
      @clr = color(0, 0, 255)
      @fr = 10
      frameRate(@fr)   # make frameRate 10 FPS
    else
      @clr = color(255, 0, 0)
      @fr = 30
      frameRate(@fr)   # make frameRate 30 FPS
    end
    @rectX = 0
  end
  fill(@clr)
  rect(@rectX, 40, 20, 20)
end