richard hockey

You will have to make use of some sort of server-side form handling
(ASP/ASP.Net/fpse/PHP/Coldfusion/CGI) to process the form.

* Client-side* javascript can't be used to write to files on the webserver
by itself, since it is executed on remote clients.

The best bet would be to see which server-side facilities your webserver
supports, and then check with the appropriate newsgroup.

If you are running the server yourself, IIS supports ASP as standard, and
can easily run PHP, Coldfusion and FrontPage Server Extensions. PHP is the
best choice if you are using Apache.