Componetnts in HorizontalLayout displayed vertically

Hi,
I want to display some components horizontally, but all component added to HorizontalLayout displayed vertically.
This is my code

import com.vaadin.ui.HorizontalLayout;
import com.vaadin.ui.Label;
import com.vaadin.ui.VerticalLayout;

@SuppressWarnings(“serial”)
public class ProfessorInfo extends VerticalLayout {

private VerticalLayout uperSection = new VerticalLayout();
private HorizontalLayout lowerSection = new HorizontalLayout();

private VerticalLayout menuSection = new VerticalLayout();
private VerticalLayout contentSection = new VerticalLayout();

//constructor
public ProfessorInfo() {
	uperSection.addComponent(new Label("Header"));
	menuSection.addComponent(new Label("Menu"));
	contentSection.addComponent(new Label("Content"));
	lowerSection.addComponent(menuSection);
	lowerSection.addComponent(contentSection);
	addComponent(uperSection);
	addComponent(lowerSection);	
}	

}
I made a Vaadin portlet by using Liferay SDK and eclipse-jee-indigo-SR1-linux-gtk-x86_64
I have Liferay 6.2 and Vaadin 7

The attached file is what displayed.

What is wrong?
any advise is much appriciated
14148.png

You need to add your components to the horizontal layout.

    private VerticalLayout verticalUperSection = new VerticalLayout();
    private VerticalLayout verticalMenuSection = new VerticalLayout();
    private VerticalLayout verticalContentSection = new VerticalLayout();

    private HorizontalLayout horizontalLowerSection = new HorizontalLayout();

    public ProfessorInfo() {
        verticalUperSection.addComponent(new Label("Header"));
        verticalMenuSection.addComponent(new Label("Menu"));
        verticalContentSection.addComponent(new Label("Content"));

        horizontalLowerSection.addComponent(verticalUperSection);
        horizontalLowerSection.addComponent(verticalMenuSection);
        horizontalLowerSection.addComponent(verticalContentSection);

        addComponent(horizontalLowerSection);
    }

Thank you very much for your response,
But, I want to have vertical and horizontal components like my code.
My problem is about liferay CSS, I have to change CSS in liferay themes.