use err630_contour_fill_line.nc

!============================================
shade/lev=(-INF)(2,10,1)(INF)/key a
frame/file=err630_contour_fill_line_01.gif

! thinks are ok 
pause

!============================================
shade/line/lev=(-INF)(2,10,1)(INF)/key a
frame/file=err630_contour_fill_line_02.gif

! some contour lines are missing
pause

!============================================
fill/line/lev=(-INF)(2,10,1)(INF)/key a
frame/file=err630_contour_fill_line_03.gif

! some contour lines are missing and
! filled areas have different colors whereas levels are the same