/replace example.com with yoour domain name, ns1 with your DNS server name.
// The number before IN PTR example.com is the machine address of the DNS server. in my $
@ IN SOA ns1.q3ait.org. (
                        2006081401;
                        28800;
                        604800;
                        604800;
                        86400
)

                     IN    NS     ns1.q3ait.org.
102                    IN    PTR    q3ait.org