title: Listen to Browser's requests
body: <p>Using the following code:</p>
  
  <pre><code>HttpListener listener = new HttpListener();
  //listener.Prefixes.Add("http://*:80/");
  listener.Prefixes.Add("http://*:8080/");
  listener.Prefixes.Add("http://*:8081/");
  listener.Prefixes.Add("http://*:8082/");
  listener.Start();
  HttpListenerContext context = listener.GetContext();
  HttpListenerRequest request = context.Request;
  </code></pre>
  
  <p>The program hangs on the <code>GetContext();</code> despite loading http (not https) pages in IE and Firefox.</p>
  
  <p>When I uncomment the first line I get the error:</p>
  
  <blockquote>
    <p>Failed to listen on prefix 'http://*:80/' because it conflicts with an
    existing registration on the machine.</p>
  </blockquote>
  
  <p>So how do I listen to a browser's requests?</p>