[R] filled.contour help

[m p]

Hello,
I plot with filled.contour and have this problem.
There is an area that I want to cover with angled
shading lines to represent NA in my data. 
Very much appreciate help. 
Thanks,
Mark


pal <- palette(gray(seq(1.,0.,len=8)))
filled.contour(fvec,qvec,etsarray,
     
levels=c(-.6,-.4,-.2,,0.,.2,.4,,.6,.8,,1.),zlim=c(-.6,1),
               xlab=xstring,ylab=ystring,
              
col=pal,key.axes=axis(4,c(-.6,-.4,-.2,0.,.2,.4,.6,.8,1.)))