Michel,

ZOrder is the 3rd dimension of the control. ie what's on top of other objects. even though all the objects are on the same XY plane.

>What a stupid name "ZOrder". Whoever thought of something so
>unintuitive ! Something like FrontOrBack with a parameter of
>TRUE or FALSE, say, would have been far more intuitive than ZOrder,
>particularly since, in addition, it is not well explained in the
>Microsoft documentation either.