public void buttonClick(ClickEvent event) {
Label mainComponent = new Label("Main");
Label header = new Label("Header");
final Label anotherComponent = new Label("another");
layout.addComponent(mainComponent, "body");
layout.addComponent(header, "loginUser");
button.addListener(new Button.ClickListener() {
@Override
public void buttonClick(Button.ClickEvent event) {
layout.addComponent(anotherComponent, "body");
layout.removeComponent("loginUser");