Continue

My program is giving no errors but it is not able to implement the continue operation instead it always shows the new game of difficulty easy.My code is as follows:

Game.java

public class Game extends Activity { private static final String TAG=”Sudoku”; public static final String KEY_DIFFICULTY=”sudoku.game.difficulty”; public static final int DIFFICULTY_EASY=0; public static final int DIFFICULTY_MEDIUM=1; public static final int DIFFICULTY_HARD=2; private int puzzle[]=new int[9*9]; private PuzzleView puzzleView; private static final String PREF_PUZZLE=”puzzle”; protected static final int DIFFICULTY_CONTINUE=-1;

@Override protected void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); Log.d(TAG,”onCreate”); int diff=getIntent().getIntExtra(KEY_DIFFICULTY, DIFFICULTY_EASY); puzzle=getPuzzle(diff); calculateUsedTiles(); puzzleView=new PuzzleView(this); setContentView(puzzleView); puzzleView.requestFocus(); getIntent().putExtra(KEY_DIFFICULTY, DIFFICULTY_CONTINUE); }
//....

@Override
protected void onPause(){ super.onPause(); Log.d(TAG, “onPause”); Music.stop(this);

getPreferences(MODE_PRIVATE).edit().putString(PREF_PUZZLE, toPuzzleString(puzzle)).commit();
}

//...

private int[]getPuzzle(int diff){ String puz; switch(diff){ case DIFFICULTY_CONTINUE: puz=getPreferences(MODE_PRIVATE).getString(PREF_PUZZLE, easyPuzzle); case DIFFICULTY_HARD: puz=hardPuzzle; break; case DIFFICULTY_MEDIUM: puz=mediumPuzzle; break; case DIFFICULTY_EASY: default: puz=easyPuzzle; break; } return fromPuzzleString(puz); }

Sudoku.java

public void onClick(View v) { // TODO Auto-generated method stub switch(v.getId()){ case R.id.button3: Intent i=new Intent(this, About.class); startActivity(i); break; case R.id.button2: openNewGameDialog(); break; case R.id.button4: finish(); break; case R.id.button1: startGame(Game.DIFFICULTY_CONTINUE); break; }

Please help me to resolve my problem.
Thanks in advance