private Position getField(int xPos, int yPos) {
    int rectSize = myBoard.getRectSize ();
    int x, y;
    if ( myBoard.getPerspective () == WHITE ) {
      x = ( xPos / rectSize ) + 1;
      y = ( yPos / rectSize ) + 1;
    }
    else {
      x = AMOUNT_OF_CELLS - ( xPos / rectSize );
      y = AMOUNT_OF_CELLS - ( yPos / rectSize );
    }

    if ( x > AMOUNT_OF_CELLS || x < 1 || y > AMOUNT_OF_CELLS || y < 1
        || xPos < 1 ) {
      // position is not on the GameField!!
      return null;
    }
    else {
      return ( new Position (x, y) );
    }
  }