private boolean checkSolution() {
      boolean isRight = true;
      StringBuilder builder = new StringBuilder();
      if (riddle != null && solutions != null) {
         for (int row = 0; row < riddle.getHeight(); row++) {
            for (int column = 0; column < riddle.getWidth(); column++) {
               if (matrix[row][column] != solutions[row][column]) {
                  if (matrix[row][column] != '*') {
                     if (builder.length() == 0) {
                        builder.append("Fehler an Folgenden Koordinaten:\n");
                     }
                     builder.append("Reihe:" + (row + 1) + " Spalte:" + (column + 1) + "\n");
                  }
                  isRight = false;
               }
            }
         }
      } else {
         builder.append("Es ist kein Rätsel vorhanden!");
         isRight = false;
      }
      wrongCoordinates = builder.toString();
      return isRight;
   }