GwtCommand command = new GwtCommand(logoutCommandName);
GwtCommandDispatcher.getInstance().execute(command, new CommandCallback() {
public void execute(CommandResponse response) {
if (response instanceof SuccessCommandResponse) {
SuccessCommandResponse successResponse = (SuccessCommandResponse) response;
if (successResponse.isSuccess()) {
userToken = null;
Authentication.this.userId = null;
manager.fireEvent(new LogoutSuccessEvent());
loginUser(userId, password, callback);
} else {