Changing cursors

[Kirk Waters <kirk waters noaa gov>]

Maybe I've just missed it in all the documentation and the FAQ, but I
haven't come across anything about how to change the cursor.
Specifically, I'm looking to change the arrow cursor to an hourglass
during a long calculation.  Is this something that needs to be done
using X calls (or Windows calls when porting)?  My apologies if the
documentation on this is in some painfully obvious place that I missed.

Thanks,
Kirk