title: asmx web service: client authentication
body: <p>I have a web service with a bunch of methods that I'd like to somewhat secure.
  The data is not really all that confidential, but I'd still like to <strong>restrict access to only those who use a certain user id and password that's stored in the web services web.config file</strong>. A C# Windows service client will be calling this web service once a day or week.</p>
  
  <p>Can anyone post a simple example of how I can do this? Thanks in advance.</p>