Nifty Gui doesn't react to input

Good morning! I'm trying Nifty Gui with Slick2d. Everything works correct besides input polling by Nifty Gui. It doen't react at all! Here is part of my code:

Xml:

<nifty xmlns="http://nifty-gui.lessvoid.com/nifty-gui">
    <screen id="GamePlay" controller="GamePlayScreenController">
        <layer childLayout="vertical">
            <panel id="roomListPanel" width="100%" height="32px" 
            childLayout="absolute-inside" padding="5px">

                <control id="appendButton" name="button" label="Pause">
            <interact onClick="test()" />       
        </control>
            </panel>
        </layer>
    </screen>
</nifty>

Java:

class GamePlayScreenController implements ScreenController {
    public void bind(Nifty nifty, Screen screen) {
        System.out.println("Bind");
    }

    public void onEndScreen() {
        System.out.println("End");
    }

    public void onStartScreen() {
        System.out.println("Start");
    }

    public void test() {
        System.out.println("Test");
    }
}

... 

// In my state class:

this.nifty = new Nifty(new LwjglRenderDevice(), new NullSoundDevice(),       new LwjglInputSystem(), new TimeProvider());

this.nifty.loadStyleFile("nifty-default-styles.xml");
this.nifty.loadControlFile("nifty-default-controls.xml");
this.nifty.registerScreenController(new GamePlayScreenController());
this.nifty.fromXml("data/test.xml", "GamePlay");
this.nifty.gotoScreen("GamePlay");

...

this.nifty.update();

... 

SlickCallable.enterSafeBlock();
this.nifty.render(false);
SlickCallable.leaveSafeBlock();

I have no ideas, why it doesn't. Please, help! Thanks!

This should work for you:

    protected void initGameAndGUI(GameContainer arg0, StateBasedGame arg1) {

    LwjglInputSystem inputSystem = new LwjglInputSystem();

    try {
        inputSystem.startup();
    } catch (Exception e) {
        e.printStackTrace();
    }           
    PlainSlickInputSystem psis = new PlainSlickInputSystem();
    GameClient.app.getInput().addListener(psis);    

    prepareNifty(nifty, arg1);
    nifty = new Nifty(new LwjglRenderDevice(), new NullSoundDevice(),psis, new AccurateTimeProvider());
    NullSoundDevice(),psis, new AccurateTimeProvider());    
    initNifty(arg0, arg1, psis);    
    nifty.fromXml("...");

}

and ofcourse

nifty.update();

in your update method.

I was using Slick2d Nifty integration.