At 01:32 PM 11/21/03 +0100, you wrote: >a way to know if there's changes, it's a flag set to 1 at each call of the >function that adds action in the undo list. 1) There's already a counter for the number of undo steps, 2) Undo only works for mesh editing, and 3) only for 1 mesh at a time. So it is not a global determiner of file changes. Bob