whereis: DNS lookup failure script

I know someone has made one, but I really never seemed to need one until
now.  I need a small script that runs on my HP-UX that constantly checks
for failures in my nameserver.. or in pinging any of my named.cache root
servers.  

With the DNS hell of this last week...  I need a program that will alert me
(either via email or TALK or whatever gets my attention.. ) when our
lookups start failing, or root servers become inaccessible.  I suppose I
could write one.. but like every other admin out there... I don't have
time.  If no utility script exists (I know it must), then I will HAVE to
write one.. which means I have to re-priortize (what else is new?).

The script could also run on any of our other UNIX machines: SCO, SUN, or
Solaris.

Let me know if you guys have any ideas or leads.
--
Virtus Tentamine Gaudet

Derek Pence
Omegaware Technologies
derek.pence@cesoft.com
vilya@ecity.net