Asmack block user Null pointer

Hi guys,

I'm trying to develop messenger using asmack that have feature block / blacklist user

but i'm getting trouble using it.

My code :

public void blockUser(String userName)

    {

        String listName = "newList";

        List<PrivacyItem> privacyItems = new Vector<PrivacyItem>();

        PrivacyItem item=new PrivacyItem(PrivacyItem.Type.jid.toString(), false, 1);

        item.setValue(getJIDofUserID(userName));

        privacyItems.add(item);

        PrivacyListManager privacyManager = PrivacyListManager.getInstanceFor(mConnection);

        try

        {

            privacyManager.createPrivacyList(listName,privacyItems);

        }

        catch(Exception e)

        {

            Log.e("ERROR: "," "+e.toString());

            e.printStackTrace();

        }

    }

I'm getting Null at  PrivacyListManager privacyManager = PrivacyListManager.getInstanceFor(mConnection);

eventhough my mconnection not null..

the impact is it will enter exception and give NULL pointer message.

any suggestion?

Thx