FUNCTION

Specify the top edge of a window. Usually, you shouldn't define a pixel value here but instead use one of the following macros:

MUIV_Window_TopEdge_Centered:
window appears centered on the visible area of screen.

MUIV_Window_TopEdge_Moused
window appears centered under the mouse pointer.

MUIV_Window_TopEdge_Delta(p)
window appears p pixels below the screens title bar.

Default for this tag is MUIV_Window_TopEdge_Centered.

As long as your window has a window id (MUIA_Window_ID), choosing a position is not that important. MUI will always remember a windows last position and size and these values will simply override your settings. Positioning and sizing should be completely under user control, a programmer doesn't need to worry about it.