public void change_board(Board b){
		reset();
		n_cell = 0;
		BLACK_SCORE = 0;
		WHITE_SCORE = 0;
		for(int i=0; i<8; i++){
			for(int j=0; j<8; j++){
				if (b.get(i, j)==BLACK_PIECE){
					board[i][j].set_value(b.get(i, j));
					n_cell++;
					BLACK_SCORE++;
				}else if(b.get(i, j)==WHITE_PIECE){
					board[i][j].set_value(b.get(i, j));
					n_cell++;
					WHITE_SCORE++;
				}
			}
		}
		this.setChanged();
		this.notifyObservers();
	}