Make a "Drawer" on MacOS X stack ?

[Ludovic Th=?ISO-8859-1?Q?=E9?=bault]

I want to make a stack with an drawer (as bookmarks or History on
Omniweb...)

I created a substack (without decorations), make a button to drag it,
that's Ok, but how let this stack in background even if i drag it
without  change the mainstack to palette ?

Thanks

-- 
Ludovic THEBAULT
(Sorry for my poooor english :-)