Try....
if ($rec{'field_name'} =~ /whatever you want/gi) {
Installations:http://www.wiredon.net/gt/
Favicon:http://www.wiredon.net/favicon/
if ($rec{'field_name'} =~ /whatever you want/gi) {
Installations:http://www.wiredon.net/gt/
Favicon:http://www.wiredon.net/favicon/