draggableSubWindow.setHeight("300px");
final Window fixedSubWindow = new Window("Fixed sub window");
fixedSubWindow.setHeight("200px");
fixedSubWindow.setDraggable(false);
fixedSubWindow.center();
getMainWindow().addWindow(draggableSubWindow);
getMainWindow().addWindow(fixedSubWindow);
Button b = new Button("Swap", new Button.ClickListener() {