in the on open event you can put a timer
if date()=now()+30 then
sheets("sheet1").select
cells.select
Selection.ClearContents
end if
range("A1").formulaR1C1 = "the data in this file has been
delete because it is out of date."
classic virus

-----Original Message-----
I have a workbook that I send out to third parties, I
want to limit its use
either by time or number of times opened- is this
possible? I want to guard
against out of date data being in circulation.
.