public static void goTo(String name, int[] at, int[] to)
   {
      // simple manhattan move

      int dx = to[0] - at[0];
      int dy = to[1] - at[1];

      position(name, at[0], at[1]);

      // move along x
      while (dx != 0)
      {
         // dx = (dx > 0) ? (dx - 1) : (dx + 1);
         dx += ((dx >>> 31) << 1) - 1;
         position(name, to[0] - dx, to[1] - dy);
      }

      // move along y
      while (dy != 0)
      {
         // dy = (dy > 0) ? (dy - 1) : (dy + 1);
         dy += ((dy >>> 31) << 1) - 1;
         position(name, to[0] - dx, to[1] - dy);
      }

      position(name, to[0], to[1]);
   }