Trademarks and domain names/misspelled?

i got a domain name it atvsconnection.com
it sell parts for scooters atvs go carts.

there another site named atvconnection.com
its a infomation site a forum and the sell advertising.
how can i check if they are a trademark.
and im i just asking for trouble.with this name

Better still, trademark your domain. This is aggressive protection on your name/domain.

Check the trademark office ..here is the link:
http://tess2.uspto.gov/bin/gate.exe?f=te...

I checked...no trademark for atvsconnection, atvsconnection or atvsconnection.com, atvconnection.com or atv connection,

so you should have no problem!