Fatal Exception and No Such table found exception in Android ,please resolve

I am getting first Fatal Exception in main , and then a No such table found Exception in my application . I know this type of questions have already been asked before but if anyone can give a specific answer to my problem , would be very great. My code is :

public class driverdb extends SQLiteOpenHelper {

public static final String DB_NAME = "driver";
public static final int DB_VERSION = 2;

public static final String TABLE = "driver";

public static final String _ID = "_id";
public static final String DRIVERNAME = "drivername";
public static final String DRIVERMOBILENO = "drivermobileno";
public static final String LICENSENO = "licenseno";
public static final String BASENO = "baseno";

public static final String CREATE = "create table " + TABLE + "(" + _ID
        + "Integer primary key autoincrement," + DRIVERNAME + "text,"
        + DRIVERMOBILENO + "text," + LICENSENO + "text ," + BASENO
        + "text)";

SQLiteDatabase db;
Context context;

public driverdb(Context context) {
    super(context, DB_NAME, null, DB_VERSION);
    // TODO Auto-generated constructor stub
}

@Override
public void onCreate(SQLiteDatabase db) {
    // TODO Auto-generated method stub

    db.execSQL(CREATE);

}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    // TODO Auto-generated method stub

}

public void readdata() {

    db = getReadableDatabase();

}

public void writedata() {
    db = getWritableDatabase();

}

public void close() {
    db.close();

}

public long Insert(drivermodel e1) {
    ContentValues cv = new ContentValues();
    cv.put(DRIVERNAME, e1.getDrivername());
    cv.put(DRIVERMOBILENO, e1.getDrivermobileno());
    cv.put(LICENSENO, e1.getLicenseno());
    cv.put(BASENO, e1.getBaseno());
    long d = db.insert(TABLE, null, cv);
    return d;

}

public Cursor getdata() {
    try {

        return db.query(TABLE, new String[] { _ID, DRIVERNAME,
                DRIVERMOBILENO, LICENSENO, BASENO }, null, null, null,
                null, null);

    } catch (SQLException e) {
        // TODO: handle exception
        Log.e("Exception on query", e.toString());
        return null;
    }
}

}

And error is on line 74 and 49. please if anyone can give a specific solution would be very helpful.