ui.Interface.getRootNode
Get the root DOM node of the abstract user interface.
Syntax
ui.Interface.getRootNode()
  RETURNS om.DomNodeUsage
The ui.Interface.getRootNode() method returns the root DOM node of the
   abstract user interface tree.
Define a variable of the type 
om.DomNode to receive the result of this method.
DEFINE rn om.DomNode
LET rn = ui.Interface.getRootNode()
-- use d to inspect/change the AUI treeExample
MAIN
    DEFINE rn om.DomNode
    MENU "Test"
       COMMAND "Display AUI"
          LET rn = ui.Interface.getRootNode()
          DISPLAY rn.toString()
    END MENU
END MAIN