I got problem in Hosting Account Main Domain Modification

[mjsanish68]

I try to modify my host account main domain but it message me "The domain you have supplied is already in use". I supply my own domain name which i have try previously in this x10hosting and then i modified that to free x10Hosting sub-domain as my account's main domain. Now i want to modify main domain into my own domain name.
I try in same host account, And then i also try in new free host account but i am not able to modify my main domain name in to my own domain name. Please, tell me in what way i can change my domain in to my own domain name?

[stpvoice]

Hello,

What is the domain name you're referring to?