Event handler for list-boxes
[C++]
virtual void OnListBox(
   UINT id,
   int nCurSel,
   const CXlControlListBox* ctl
);
ID of the list-box.
New selection of the list-box.
Pointer to the control which originated the event.
This overrideable function is called whenever the current selection of
            a list-box
            (CXlControlListBox)
            is changed by the user.
            Note that it will only be called if the list-box
            has been set to trigger events 
            (see CXlControl::SetTrigger()).
             Its default behaviour is to do nothing.
            
Header: xldialog.h