title: How to detect authenticated user with FormsAuthentication?
body: <p>How do I tell if a user is authenticated (logged in) using FormsAuthentication?</p>
  
  <pre><code>&lt;authenticaion mode="Forms"&gt;
     &lt;forms protection="All" cookieless="UseCookies"/&gt;
  &lt;/authentication&gt;
  </code></pre>