MACROMEDIA DIRECTOR MX 2004-DIRECTOR SCRIPTING Reference page 202

An
on zoomWindow
window dimensions change.
Example
This handler moves sprite 3 to the coordinates stored in the variable
window that the movie is playing in is resized:
-- Lingo syntax
on zoomWindow
centerPlace = point(10, 10)
sprite(3).loc = centerPlace
end
// JavaScript syntax
function zoomWindow() {
var centerPlace = point(10, 10);
sprite(3).loc = centerPlace;
}
See also
drawRect, sourceRect,
202 Chapter 10: Events and Messages
event handler is a good place to put Lingo that rearranges sprites when
on resizeWindow
when the
centerPlace