title: Detecting Web.Config Authentication Mode
body: <p>Say I have the following web.config:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;configuration&gt;
      &lt;system.web&gt;
          &lt;authentication mode="Windows"&gt;&lt;/authentication&gt;
      &lt;/system.web&gt;
  &lt;/configuration&gt;
  </code></pre>
  
  <p>Using ASP.NET C#, how can I detect the Mode value of the Authentication tag?</p>