ok , my dedicated hostname is mydomain.com and my nameservers are ns1.mydomain.com and ns2.mydomain.com, he will need to change his domain dns setting at the registrar to ns1.mydomain.com and ns2.mydomain.com for his main domain, then he can have his own ns.hisdomain.com ? will i need to add this ns.hisdomain.com somewhere in whm ? thanks a lot for your patience