Not able to bind service in activity

Question

I am binding service from SherlockFragment and binding service in it but connection is not establishing.

private ServiceConnection connection = new ServiceConnection() {      

    @Override
    public void onServiceConnected(ComponentName arg0, IBinder arg1) {
        service = ISipService.Stub.asInterface(arg1);
        System.out.println("Inside Connection"+service);
    }

    @Override
    public void onServiceDisconnected(ComponentName arg0) {
        service = null;
    }
};

Control is never go inside onServiceConnected()

Any help/suggestion would be appreciated.