Preventing "Entire Grid Undefined"?

[Jim Benedict]

GrADS users,

Does anyone know of a way to prevent GrADS from printing "Entire Grid
Undefined" on plots?  I have a script that shades areas that are
statistically significant using the maskout function, and in some
cases there is no significance -- making the entire grid actually
undefined.  However, I'd rather not have the printed warning on the
plot.

Thanks in advance,
Jim Benedict