Hi, John.

>Actualy I am not very sure what things I could implmenet as addin. However, I would like to know what could be and try to implement to get it's benefit. COuld you please to share?


Add-ins are tipically custom extensions to some piece of software that are usually entirely optional and oriented to very specific purposes.

For example, HTML editors normally have many available add-ins to let you insert special features in web pages. There are roll-over, calendar, photo-album, menu-generators, and lots of other add-ins.

VFP support add-ins for its Class Browser. I remember an add-in to copy a class and all its dependencies to a separated folder.

Or you can take the concept further and take an approach like the one in VFP 8 TaskPane Manager, that allows third parties to build and add custom Panes (you can download several from www.TaskPane.com). In this case they are not called add-ins, but the concept is simmilar. Builders could be considered a very specific add-in implementation.

>In my mind, I think that addin should be for those optional features such as web update or replication may be.... any others??

Those are things that tipically are not so optional and tend to be integral part of a product. If what you want to try is web updates, take a look at this excellent article from Rick Strahl:
http://www.west-wind.com/presentations/wwCodeUpdate/codeupdate.asp

Feel free to ask me any further question.

Best luck,