if (x>width) x = width-5;
      if (x<0) x = 5;
      if (y<0) y = 5;
      if (y>height) y = height-5;
  
      fill(r, g, b);
      stroke(r, g, b);
      noStroke();
      ellipse(x, y, 10, 10);
      strokeWeight(10);
      line(oldX, oldY, x, y);
      noStroke();
    }
  }
  
  </script>