void RefillRackBoard(Board board)
{
int emptyTilesNo = pieceManager.CheckEmptyTiles(rackBoard);
pieceManager.Setup(board, emptyTilesNo);
letterCount -= emptyTilesNo;
score += emptyTilesNo;
lettCountTextField.text = "TILES LEFT : " + letterCount.ToString();
scoreTextField.text = "SCORE : " + score.ToString();
}