How to redraw the window (stage) in Java FX 2.2

I need to redraw a window when selecting combo box elements

Here is my code

functionCombo@R_683_2419@.valueproperty().addListener(new changelistener<String>() {
    @Override public void changed(ObservableValue ov,String t,String t1) 
    {
        showFunctionParamters(t1);
    }
    private void showFunctionParamters(String methodName) 
    {
        gridPaneParameters = new GridPane();
        gridPaneParameters.setPadding(new Insets(20,50));
        gridPaneParameters.setHgap(10);
        gridPaneParameters.setVgap(4);
        int i = 2; 
        parameterList = methodAttrMap.get(methodName);
        Iterator<String> itrParameterList = parameterList.iterator();
        while(itrParameterList.hasNext())
        {
            //TODO allow the user to enter the values for the parameters 
            Label parameterName = new Label(itrParameterList.next()); 
            TextField parameterTextField = new TextField();
            gridPaneParameters.add(parameterName,1,i);
            gridPaneParameters.add(parameterTextField,2,i);
            i++;
        }
        pane.getChildren().add(gridPaneParameters);
    }
});

Solution

Because your code adds new components to the pane at run time, you may need to:

pane.requestLayout();