Within my <mx:Application> I immediately have a <mx:VBox> wrapper around the rest of my content. The idea is to have the VBox expand/collapse depending on the height of the page I am viewing. I have several pages of various heights. The problem is that the VBox takes on the height of the contents within the initial page that I am viewing, and does not expand or collapse when I view other pages with content of different heights. How do I make a <mx:VBox> collapse/expand to fit its content?