Keeping the list of search domains in /etc/resolv.conf, using DHCP

[Bart van Kuik <BART VAN KUIK ORACLE COM>]

I'm using RedHat 9 and I'm using DHCP. This client deletes any additions
to the domains to be searched in the /etc/resolv.conf file. Is there a setting
somewhere which prevents the client from deleting manual additions to
the /etc/resolv.conf file? I.e. the contents are initially:

search domain1.com
nameserver 1.2.3.4
nameserver 1.2.3.5

Then I add two extra domains to be searched, like this:
search domain1.com
search domain-x.net
search domain-y.org
nameserver 1.2.3.4
nameserver 1.2.3.5

and after the DHCP client runs, the extra lines are deleted. How to
prevent this?

TIA
Bart