User Search on Extra Attributes

Hello, I need to search an user on my Openfire Server by extra attributes,

Currently I perform a research in this way:

usm = new UserSearchManager(mApplication.getConnection());  //user manager
Form searchForm = usm.getSearchForm("search." + mApplication.getConnection().getServiceName());
Log.e("user", search_user);
Form answerForm = searchForm.createAnswerForm();
answerForm.setAnswer("Username", true); answerForm.setAnswer("search", search_user);
ReportedData data = usm.getSearchResults(answerForm, "search."+mApplication.getConnection().getServiceName()); Iterator<ReportedData.Row>  itr= data.getRows();

It works, but if I need to perform a research based on an extra field (ex. Address), I can’t retrieve the user

Map<String, String> mp = new HashMap<String, String>();                                mp.put("address", "California");                                 newAccount.createAccount(userName, psw, mp);

Can somebody help me?