code for rotecting program

[rainbow]

hello,

Ineed a code for protecting my program made in access .what i need is the way how to limit my program ex:2 month and if the buyer pays for then i can release for few more months,and if not paid i want that program after expiration of time to be closed (locked) automatically.

Thanks

[DKenny]

I have an Excel model published on a website that needs to expire every 3 months and then gets replaced with a new version.
To achieve this I have a constant in my code called "ExpireDate" which I set to the date I want the model to expire.
I also have a Boolean variable called "Expired" which is set as follows when the file is opened.

Expired = (Now >= ExpireDate)

For each Sub in the model I include the following code before the main code is run.

If expired Then
    MsgBox "This model has expired, please visting the home page for the latest version"
    Exit Sub
End If

This prevents any code from running after the expire date.