I'm developing a website in php that allows members to create blogs similar to blogger.com. When a visitor creates an account at my website they are given a unique parameter ID which distinguishes their blog/accounts from others. For example blogs.com?id=2 I would like to make it so they can link their own domain name to the account they created on blogs.com. So instead of using blogs.com?id=2 they would just enter their domain name and it would associate itself with blogs.com?id=2. How do I perform this relationship? I'm assuming they will first have to change their CNAME to point to my name server (NS1.blogs.com).