function check_cancel
@common_blocks.inc
stit = 0
;a = get_kbrd(0)
; ; uncomment this line if the codes breaks with get_kbrd (there was a
; bug in mac os Leopard where this was necessary) should be fine now.
;a= ''
;if N_elements(a) gt 0 then $
;  if (a[0] eq 'c' or a[0] eq 'C') then begin
;    stit = 1
; endif
event = widget_event(CANCEL_BUTTON, /nowait)
eventName = Tag_Names(Event, /Structure_Name)
if eventName  eq "WIDGET_BUTTON" then $
   if event.id eq cancel_button then begin
   stit = 1
   print, 'CANCELED by presing cancel button in gui!'
endif
return, stit
end