Get Panels to a predefined size ?

I have this “window” to which I want to add two panels side by Side and make then take 40 % and 60% of the window’s width respectively.

The following is the code that I think should do it, but the panel don’t fill up the windoq, sorry if this is too naive, I’m still transitioning from the html world to vaadin.(BTW, TestWindow is a child of the Main Application Window)

public class TestWindow extends Window {
Panel menuPanel;
Panel formPanel;

public TestWindow(){
	this.setUpLayout();	
}

private void setUpLayout(){
	this.setWidth("90%");
	this.setHeight("90%");		
	this.center();	
	HorizontalLayout layout = new HorizontalLayout();
	layout.setSizeFull();
	menuPanel = new Panel();
	formPanel = new Panel();
	menuPanel.setSizeFull();
	formPanel.setSizeFull();
	menuPanel.setWidth("40%");
	formPanel.setWidth("60%");
            menuPanel.setHeight("90%");
	formPanel.setHeight("90%");
	layout.addComponent(menuPanel);
	layout.addComponent(formPanel);
	this.addComponent(layout);
	
}

}

Sorry Guys , I jumped the gun in posting - I should’ve just used the expansion ratio. So for anyone who is looking for this info the code must be

private void setUpLayout(){
this.setWidth(“90%”);
this.setHeight(“90%”);
this.center();
HorizontalLayout layout = new HorizontalLayout();
layout.setSizeFull();
layout.setMargin(true);
menuPanel = new Panel();
formPanel = new Panel();
menuPanel.setSizeFull();
formPanel.setSizeFull();
layout.addComponent(menuPanel);
layout.addComponent(formPanel);
this.setContent(layout);
layout.setExpandRatio(menuPanel, 1);
layout.setExpandRatio(formPanel, 3);
}