Hello;
In order to use a different domain, (such as .co.cc), you must register that domain name.
In the case of a .co.cc you would need to register the new domain (free) at
http://www.co.cc/
More information on using your own domain can be found in
This Article.
Your also need to be aware that after changing your domain your domain you must wait for DNS propagation which can take 24 to 48 hours and during this time your website may or may not be accessible on the Internet at any given moment.
At the present time you have a .co.cc domain listed as your main domain but that domain is not registered at .co.cc so you will not be able to use that domain until you properly register it and change your nameservers at .co.cc to point to ns1.x10hosting.com and ns2.x10hosting.com
You will need to either register the .co.cc domain name you have listed as your main domain and change the nameservers or change your main domain back to your original .x10.mx address.
Whatever you decide to do your website may not be accessible for 24 to 48 hours due to the propagation process.