How can I block IP address range with sshd_config

[Michael Sullivan]

The kiddies using their script file to try to hack into my systems
through sshd using accounts guest and test tried again yesterday.  This
morning I opened up the man page for sshd_config in Konquerer (the
colour coding is very nice) and discovered how I could deny access
through ssh from all accounts except the accounts that might use it
(this excludes guest and test).  The other day I went in to each of the
user accounts and modified their .bashrc file so that when they log in
it asks them to change their password and boot them out.  This will work
for now because for now the enemy script is only trying to inquire about
the nonexistent guest and test accounts.  The IP addresses they try to
log in from vary slightly, but for the most part I think the first three
octets are the same.  I looked through the man page for sshd_config for
a way to block their IP, but I couldn't find it.  Does anyone here know
how to do this?