public void setPos(ChessPosition pos) {
		if (state != GameState.PLAYING) {
			System.out.println("finish game: " + state);
			return;
		}
		if (isChooseForMove(pos)) { // chon quan de di chuyen
			// loai bo pos khong hop le
			if (board.getPiece(pos) == 0)
				return;

			oldPos = pos; // neu hop le thi danh dau oldPos da chon
			newPos = null;
			updatePosCanMove();

		} else if (oldPos != null) { // neu da co pos duoc chon
			// thi di chuyen quan den vi tri moi

			// vi tri di chuyen den phai nam trong posCanMove
			boolean validPos = false;
			for (ChessPosition posCM : posCanMove) {
				if (posCM.getRow() == pos.getRow()
						&& posCM.getCol() == pos.getCol()) {
					validPos = true;
					break;
				}
			}
			if (validPos == false)
				return;

			// vi tri hop le thi tien hanh di chuyen
			newPos = pos;
			this.move(oldPos, newPos);
		}

	}