[AccessD] Techniques for creating Evaluation Version of applications

Stephen:

It's pretty simple, really.  I have a 16 character key which is stored 
in a front end table.  It's kind of encrypted but since it's not 
viewable I guess it really doesn't need to be (like I break the 
expiration date into the month part, day part, and year part, and 
convert them into three different alphabetic characters and stash them 
in non sequential characters in the key).  When the app starts, I 
decrypt the key and extract, among other things, the expiration date.  
So I just check that date against the clock/calendar and display 
'License expired' and then Application.Quit. 

Since I also store the customer's name, when the app starts one of the 
text boxes on the opening form has 'Licensed To: " & Customer Name & 
"License Expires: " & Expiration Date.

To stop them from cheating by turning back the date in the computer, 
every time the app starts I also save the current date in a table.  If 
the current date is less than the last time the app was started I don't 
allow it to start. Really elementary stuff, but it works.

As the expiration date of the app draws near, I display a pop-up which 
says 'your license will expire in xx days.  Call Beach Access Software 
for a key to extend the license'.  I have a customer tracking app which 
creates these keys based on the desired expiration date.  So, I can call 
up their record in my customer tracking app, generate a new key based on 
whatever expiration date I want, then then email them the new key which 
they enter in the pop up, and extend the license. 

The key is kind of like a Microsoft key - 6 groups of four alphanumeric 
characters.

Oh, yeah, the app is compiled into an mde and the database window is 
hidden, and the bypass key disabled and all that standard stuff.  I 
don't use drop down menus, either, so I turn off the menu bar. 

HTH,

Rocky Smolin
Beach Access Software
858-259-4334
www.e-z-mrp.com

Stephen Negus wrote:
> Hi All,
>  
> I was just wondering if anyone has any techniques that they use for
> creating evaluation versions of an Access application which "stops
> working" after a specified period of time (say 30 days) until it is
> registered (paid for).
>  
> Thanks,
>  
> Stephen 
>   

-- 
Rocky Smolin
Beach Access Software
858-259-4334
www.e-z-mrp.com