title: vaadin application menu
body: <p>I have a vaadin application that redirect after login to a view with header / left menu and a main panel.</p>
  
  <p>how can I set the menu or any link to switch the main panel according to a specific contents</p>
  
  <p>If I click contact It set ContactLayout in the main panel.</p>
  
  <p>PS: I know how to set a menu like in <a href="http://vaadin.com/book/-/page/components.menubar.html" rel="nofollow">vaadin documentation</a> but I want to know what to set as command for the menu item.</p>
  
  <p>thanks</p>