求助：wrf里边用了MainTitle但是还是显示不出来

clannand

begin
;open file
a = addfile("~/shuju/Metgrid/met_em.d01.2011-08-01_06:00:00.nc","r")
;open workstation
wks = gsn_open_wks("x11","hgtwrf2")
res = True
res@MainTitle = "ABC"
res@NoHeaderFooter = True

plres = True
mpres = True
mpres@ContourParameters = (/0,5600,100/)
mpres@mpGeophysicalLineColor = "Black"
mpres@mpNationalLineColor = "Black"
;----get variable
ter = a->HGT_M(0,:,:)

opts = res
opts@cnFillOn = True
opts@cnFillColor = (/278,109,100/)
opts@NoHeaderFooter = True
opts@InitTime = True
opts@lbTitleOn = False
opts@FieldTitle = "heightmap"
plot = wrf_contour(a,wks,ter,opts)
contour = wrf_map_overlays(a,wks,(/plot/),plres,mpres)
end

clannand

有木有大神呢，谢谢