Joel,

When you run a procedure, the Undo buffer is cleared; previous
commands cannot be undone. You can create your own Undo
procedure, but when you go to Undo in the Excel UI, only this
procedure is available. Use Application.OnUndo to assign a
procedure to the Undo action. E.g.,

Public Sub AAA()
Application.OnUndo "Undo This", "UndoProc"
' your code here
End Sub

Sub UndoProc()
' code to undo
End Sub


--
Cordially,
Chip Pearson
Microsoft MVP - Excel
Pearson Software Consulting, LLC
www.cpearson.com


"Joel" wrote in message
...
Okay, I wrote this really cool function, you see. It populates
tons of blank
cells for the end-users, saving them hour upon hours of time.
Everyone's
happy....except....

The function updates a bunch of data, but the "Undo" button is
never
activated. So, if the want to undo the data changed by my
way-cool function,
the only way for them to do it is to close the file without
saving changes
and re-open it.

How do I get my code to activate the "Undo" button, so the
changes can be
rolled back if needed?

Thanks!