Pro RunIt_Event, event
Widget_Control, event.id, Get_UValue=eventUValue
message = "Whoops, this EVENT shouldn't be in RunIt_Event!"
Catch, error
IF error NE 0 THEN BEGIN
   ok = Widget_Message(message)
   RETURN
ENDIF
IF eventUValue EQ 'BUTTON' THEN $
   Widget_Control, event.top, /Destroy ELSE $
   ok = Widget_Message(message)
END 

Pro RunIt
tlb = Widget_Base(Column=1)
button = Widget_Button(tlb, Value='DONE', UValue='BUTTON')
input1 = cw_input(tlb, Title='Saying: ', UValue='INPUT', $
Value='Vaya con Dios!')
input2 = cw_input(tlb, Title='Comment:', UValue='INPUT', $
Value='Viva la Widgets!')
Widget_Control, tlb, /Realize
XManager, 'RunIt', tlb, Event_Handler='RunIt_Event'
END