Thanks to all for your suggestions. I figured it out. It works pretty much like this:
1. place READ EVENTS in the form Activate method
2. place CLEAR EVENTS in the QueryUnload method
3. place CLEAR EVENTS just before any other procedural code in the form that causes the form to close
4. set WindowType = 1 (modal)
5. set ShowWindow = 2 (As Top-Level Form)

This will do the trick.
The purpose of the form is similar to login but not exactly the same.

Thanks again for your help.
Regards, Chaim