>>One related question comes into my mind: What is the advantage of using base >>classes like Session or, as you suggested, Cursor over using other visible or >>nonvisible base classes?

These data objects are only available as non visual classes. It makes them lighter weight.

>>Couldn't I use just a label (for instance) and add my properties and methods >>using the class designer.

The label class is not a data object.

>>I cannot even see the methods (or properties) in the properties sheet >>because, as you say, there's no designer for those. Is there a good >>documentation about those base classes that don't have a designer?

Create an instance of the cursor class and view its PEMs in the debugger.

Charlie