Layout Z-Index?
I was wondering if there is way to handle a z-index for a layout?

I'm attempting to do a more tradition menu.  I have labels for say "File", "Edit", "View", "About" etc.  I have mouse button up/down on those to either hide/show the sub-menus.  

The sub-menus are in their own layout and I can get them to show/hide easy enough.  However, when they do show up, it pushes everything else that comes after down.  Is there anyway to change the z-order on them in order to where it doesn't have that behavior?  

Or is there a better way to get a traditional menu system that would have that type of behavior inherent with it?