title: How can I authenticate to a domain?
body: <p>I've got a windows server which runs our team foundation server and my self written .NET-Webservice.
  The windows server acts inside of a domain. My webserver gets now the username and password for other computers inside of the domain. How can I authenticate them on my webservice? I want that only users, which are part of the domain, are able to work with the webservice.</p>