You can't copyright a domain name. So therefore you cant be sued successfully. Scriptlance.com should have secured all derivitives of "Scriptlance.xxx" if they wanted to keep that name to themselves. They did not, and you purchased "Scriptlance.ws". Legally its yours. You didnt clone his site, you didnt steal his graphics, you didnt infringe on anything they have on their site, so you are legally in the clear.