How to delete listview items from sqlite through Contextual Action Bar

I have this code for my database

public class DbDatabase {

public static final String KEY_ROWID = "_id";
public static final String KEY_NOTES = "notes";

// Set up the database
public static final String DATABASE_NAME = "NotesDatabase"; 
public static final String DATABASE_TABLE = "notesTable"; 
public static final int DATABASE_VERSION = 1;

private final Context myContext;
private DbHelper myHelper;
private SQLiteDatabase myDatabase;

// Set up a subclass to help set up the database
public static class DbHelper extends SQLiteOpenHelper {

    public DbHelper(Context context) {
        // TODO Auto-generated constructor stub
        super(context, DATABASE_NAME, null, 1);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub
        db.execSQL("CREATE TABLE " + DATABASE_TABLE + " (" + KEY_ROWID
                + " INTEGER PRIMARY KEY AUTOINCREMENT, " + KEY_NOTES + " TEXT NOT NULL);");
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub
        // If the table exists, drop it and than call onCreate method
        db.execSQL("DROP TABLE IF EXISTS" + DATABASE_TABLE);
        onCreate(db);

    }
}
public DbDatabase(Context c) {
    // TODO Auto-generated constructor stub
    myContext = c;
}

// Open the database
public DbDatabase open() throws SQLException {
    // TODO Auto-generated method stub
    myHelper = new DbHelper(myContext); 
    myDatabase = myHelper.getWritableDatabase(); 
    return this;

}

// Write to the database
public long createEntry(String notes) {
    // TODO Auto-generated method stub
    ContentValues cv = new ContentValues();
    cv.put(KEY_NOTES, notes);
    return myDatabase.insert(DATABASE_TABLE, null, cv);
}

}

// Close the database
public void close() {
    // TODO Auto-generated method stub
    myHelper.close();
}

public  ArrayList<String> getData() {
    // TODO Auto-generated method stub
    String[] columns = new String[] { KEY_NOTES };

    // Read info through cursor
    Cursor c = myDatabase.query(DATABASE_TABLE, columns, null, null, null,
            null, null);
    ArrayList<String> result = new ArrayList<String>();


    int iNotes = c.getColumnIndex(KEY_NOTES);

    for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext())
        // Read all the data from the beggining as far as
        // the position of the first row is not after the position
        // of the last row  

        result.add(c.getString(iNotes));

    return result;
}

}

this is my adapter

public class DbDatabase {

// Set up the columns of the database
public static final String KEY_ROWID = "_id";
public static final String KEY_NOTES = "notes";


public static final String DATABASE_NAME = "NotesDatabase";
public static final String DATABASE_TABLE = "notesTable";
public static final int DATABASE_VERSION = 1;

private final Context myContext;
private DbHelper myHelper;
private SQLiteDatabase myDatabase;

// Set up a subclass to help set up the database
public static class DbHelper extends SQLiteOpenHelper {

    public DbHelper(Context context) {
        // TODO Auto-generated constructor stub
        super(context, DATABASE_NAME, null, 1);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub
        db.execSQL("CREATE TABLE " + DATABASE_TABLE + " (" + KEY_ROWID
                + " INTEGER PRIMARY KEY AUTOINCREMENT, " + KEY_NOTES + " TEXT NOT NULL);");
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub
        // If the table exists, drop it and than call onCreate method
        db.execSQL("DROP TABLE IF EXISTS" + DATABASE_TABLE);
        onCreate(db);

    }
}
public DbDatabase(Context c) {
    // TODO Auto-generated constructor stub
    myContext = c;
}

public DbDatabase open() throws SQLException {
    // TODO Auto-generated method stub
    myHelper = new DbHelper(myContext); 
    myDatabase = myHelper.getWritableDatabase(); 
    return this;

}


public long createEntry(String notes) {
    // TODO Auto-generated method stub
    ContentValues cv = new ContentValues();
    cv.put(KEY_NOTES, notes);
    return myDatabase.insert(DATABASE_TABLE, null, cv);
}




public void close() {
    // TODO Auto-generated method stub
    myHelper.close();
}

public  ArrayList<String> getData() {
    // TODO Auto-generated method stub
    String[] columns = new String[] { KEY_NOTES };

    // Read info through cursor
    Cursor c = myDatabase.query(DATABASE_TABLE, columns, null, null, null,
            null, null);
    ArrayList<String> result = new ArrayList<String>();


    int iNotes = c.getColumnIndex(KEY_NOTES);

    for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext())

        result.add(c.getString(iNotes));

    return result;
}

}

I try through CAB to delete item i have chosen from my database. How can I delete them from my database?