commands are: 1 - center : the background appears behind you centered respect to your avatar. 2 - stop : the background disappears. 3 - shift1L : appears behind you shifted 1 step left respect to the center position. 4 - shift2L : appears behind you shifted 2 steps left respect to the center position. 5 - shift3L : appears behind you shifted 3 steps left respect to the center position. 6 - shift4L : appears behind you shifted 4 steps left respect to the center position. 7 - shift1R : appears behind you shifted 1 step right respect to the center position. 8 - shift2R : appears behind you shifted 2 steps right respect to the center position. 9 - shift3R : appears behind you shifted 3 steps right respect to the center position. 10 - shift4R: appears behind you shifted 4 steps right respect to the center position.