private void load_image(String image, int tile) {
   try {
     img[tile] = m.loadImage(image);
   } catch (Exception e) {
     System.out.println("Couldn't find image " + image);
     System.exit(-1);
   }
 }
  public void loop() {
    int i, j;

    // Draw 1st layer - the ground
    for (i = 0; i < 10; i++) {
      for (j = 0; j < 8; j++) {
        m.image(img[world[i][j]], 100 * i, 100 * j);
      }
    }
    // Draw 2nd layer - the structures.
    for (i = 0; i < 10; i++) {
      for (j = 0; j < 8; j++) {
        if (world[i][j] == HOUSE) {
          m.image(img[GRASS], 100 * i, 100 * j);
          m.image(img[HOUSE], 100 * i, 100 * j);
        }
      }
    }
  }