reducing the no. of contours

[John Guhin]

Hi, I have a high resolution dataset. When I am plotting a contour it
is showing too many contours within its range (say 100 120 140 160 by
putting under set clevs). Is there any way I can show only some of the
contours of the above four levels (not all).  I know how to limit the
contour levels, but don't know  how to set the no. of contours.  Its
not quite scientific to do so, but I just wanted to know.

john guhin