Android : Facebook post image on friend's wall using android facebook sdk 3.16

I am trying to post the image on my friends wall using the android facebook sdk 3.16. i am trying with the below.Instead of posting on my selected friend wall,it's posted on my(currently login user) wall.Can anyone help me ! Thanks in adv.

Request request = Request.newUploadPhotoRequest(session, bitmap, new Request.Callback()     {

            @Override
            public void onCompleted(Response response) {
                fbCallBack.callback();
            }
        });
        Bundle params = request.getParameters();
        params.putString("message", caption);
            params.putString("to", targetUserId);
            params.putString("from", currentUserId);


        request.setParameters(params);
        request.executeAsync();