a i found how to do this:
Repeat WaitEvent() Select EventID() Case EVENT_GADGETSELECT Select EventSource() Case editor editor_oldline=editor_curline editor_curline=TextAreaCursor(editor, TEXTAREA_LINES) EndSelect Case EVENT_GADGETACTION Select EventSource() Case editor highlighteditor (editor_oldline, editor_curline) EndSelect Case EVENT_WINDOWCLOSE Exit End Select Forever