Co.cc is a third-party domain name service that's mostly free, and it's not controlled nor owned by x10hosting so your co.cc domain isn't signed up for you. Since you didn't register it at co.cc, then that's why it's not working. That co.cc domain isn't available. Try changing it to a different one, and be sure to sign it up at co.cc and set the nameservers to:
ns1.x10hosting.com
ns2.x10hosting.com