Domain name dispute - trademark/servicemark infringement

There really isn't enough information here to give you a complete response, but trademark rights are created when a word or symbol is attached to goods or services which are offered to the public. Assuming your website displayed the same word or phrase used as your 2nd level domain name (in the web address www.Avvo.com, the trademark Avvo is the 2nd level domain name), you may have some common-law trademark rights in that word or phrase. If you do have trademark rights, then you may be able to regain the domain name under the Federal anti-cybersquatting statute. Finally, in order to obtain trademark rights, it is not necessary for you to file as a nonprofit or as a business. I would argue that you gained trademark rights by hosting a site that provided information on the specific subject to the public and that the public has come to associate your trademark with that information.