final TextBox userName = new TextBox();
form.addAttribute(constants.NewUserName(), userName);
com.google.gwt.user.client.ui.Button create = new com.google.gwt.user.client.ui.Button(constants.OK());
form.addAttribute("", create);
create.addClickListener(new ClickListener() {
public void onClick(Widget w) {
if (userName.getText() != null && userName.getText().length() !=0) {
RepositoryServiceFactory.getService().createUser(userName.getText(), new GenericCallback() {
public void onSuccess(Object a) {
refresh();