Hi Vlad,
Before you start doing too much with ZOrder(), you might want to check out p.808 of the Hacker's Guide to VFP3. The upshot is that ZOrder also controls the order that events fire in. Changing the ZOrder of a control during an event can result in hiding that event from other controls.
Later,
Ned
>You can place the object in any order at design time using the "Send to back" and "Bring to front" actions. At runtime, use ZOrder() method. So, the Controls collection is not really read-only at runtime. As said, ZOrder changes the order in the collection and AddObject and RemoveObject methods add and remove elements from the list. So, I would say that having these powerful methods to manage the collection, it is not read-only. :)