Nadya,

>This is the question: determine user's activity after he/she logs into the system. For instance, somebody logs into the system, then immediatelly switches to another application and forget about VFP application completely. Now how can I find out?

It all comes down to logging the user's actions somhow. I once worked on an app that had access to several databases. My client allowed his customers to access the app with Citrix Winframe and charge the customer based on usage. So we had hooks at several places in the app that would log when they started the app, open a specific database, close a specific database, and exit the app.

You could something similar by creating a userID property on the application object, then place a logging function in the Init() and Destroy() methods of your form base class that writes to a log file. This wouldn't be too difficult to do if it's a new app. It may be difficult to retrofit an existing app based on the class hierarchy. It's also going to create a ton of data so you'll want to include a switch to turn it off!