Screens and forms usage

Using this should be easy…or so it seemed. As far as i understand, elements on the screen are only common to those screens which are nested under the screen with those elements. But when i try to use this to create a web page with a fixed menu all elements show up on all forms. Except when i hide them, but then when i create an action to move to another form (using Behavior panel) nothing happens. Is there something i dont know?