Defining Trial Period of VBA Code

[ExcelMonkey]

Does anyone know how to write a sub routine that limits the use of a
excel spreadsheet with VBA? That is, I want to give trial versions o
my spreadsheet to people and control the number of times or tim
periods they use it. Example, you can only use this file for free fro
Jan1 to Jan 10 then you have to buy the registered version. Or you ca
only open this file 3 times for free and then you have pay for th
registered verison.

Yes I know that security is not good. But I still want to understan
how to TRY and do it

1) Define trial period (i.e. date of file expiration)
2) Define trial usage (i.e. # of file opens)

Thank

 

[Tom Ogilvy]

Search the google groups archive for microsoft.public.excel.programming
for terms such as trial period, expire, limit

http://groups.google.com/advanced_group_search?hl=en

This question comes up all the time.