ownership of websites

[talonk246]

My company focuses on small to medium local businesses in need of website updates...taking a company from html 1.0 to 2.0. My question though is that when I meet a potential client who already has a website, what is the best way to obtain the rights to use their domain or parts of their current site. My understanding is that if they didn't explicitly sign some agreement that says they own the design, domain, or content, then the original web design company owns all of it....especially if it is registered under the web designer's name. Has anyone dealt with this issue and found a good approach?

thanks for the help
Corey