Hi Tom,
following on your suggestion I have managed to get the events correct
though I would like to ask you one more favour.

basically I have built some fairly intricate excels workbooks and I
would like to release them, I would though like to allow people to use
them for say 60 days and after that if they like my work and part with
a little cash they can have a code (this could be a alfanumeric series)
that would unblock the workbook. do you think this is possible? if so
how? thank you for your efforts.
Alan