how to create a virtual subdomain system?

[Rollo_Tamasi]

a project i'm going to undertake in the summer will require a user system which generates a virtual subdomain for users who register with my site.

For example the user john signs up and is given a subdomain to access his account, john.website.com, which when rendered in the browser will automatically bring up http://website.com/profile.php?username=john or similar.

How can this be acheived? I know can it can be done with .htaccess but won't that require configuration from myself each time a new user signs up? I would like this system to be automated as much as possible. I will be developing in PHP so if anyone knows of a way to do this....

Cheers

[etully]

It's less difficult than it sounds and doesn't require any manual intervention on your part.

First, add a wildcard to your DNS that points *.yourdomain.com to your site.
Then, in your PHP scripts, just check the environment variable for the Host to see what domain was used to arrive at the page. Then you know the username. You can use that username to look up what the page should look like.