Guy,
If you do something from a MDI form than it has in my opinion the focus.
If it is from the MDIContainer than it can be something as
\\\
For Each frm As Form In Me.MdiChildren
If frm.Focused Then
MessageBox.Show(frm.Text)
End If
Next
////
This kind of things you can do as well from a MDIChild by adding
\\\
For each frm as Form in Me.MDIParent.MDIChildren
///
I hope this helps
Cor