ERROR:  When defining a user-defined widget, you  must  specify  the
  name  of  the low-level creation routine for creating an instance of
  this widget.

  USER ACTION:  Insert a procedure clause following the widget type in
  the  widget  declaration.   You  also  need  to declare the creation
  procedure using a procedure declaration.  For example:

          procedure my_list_box_creation_proc();

          object list_box1:
              user_defined procedure my_list_box_creation_proc()
                { arguments ... };