GET_INFO(WIDGET)

 For an overview of the GET_INFO built-in, see the HELP topic GET_INFO.

 The following strings can be used for parameter2 when parameter1 is the
 keyword WIDGET:

 Parameter 2      | Return Value  (Parameter 1 is the keyword WIDGET)
 -----------------+----------------------------------------------------------
 "callback_       | 1 or 0       - The value 1 if the call was encountered
 parameters"      |                within a callback procedure and
                  |                if callback information is available;
                  |                0 otherwise.  The third parameter
                  |                to this call is an array that
                  |                returns the widget instance performing
                  |                the callback, the closure value,
                  |                and the callback reason.  The arrray
                  |                elements are indexed by the the
                  |                following strings:  "widget",
                  |                "closure", "reason_code".
 "widget_id"      | Widget       - The widget instance corresponding to
                  |                the widget name that you pass in as
                  |                the fourth parameter.  Note that the
                  |                full syntax of this call is as follows:
                  |
                  |                GET_INFO (WIDGET, "widget_id",
                  |                          {parent_widget | SCREEN},
                  |                          widget_name)
                  |
 -----------------+-------------------------------------------------------------