title: How to pass credentials in defaultProxy config setting?
body: <p>A client is unable to use my webpart because he is behind a proxy server and they need to specify a username and password to get past the proxy.  I have this in my config file right now:</p>
  
  <pre><code>&lt;system.net&gt;
      &lt;defaultProxy&gt;        
        &lt;proxy usesystemdefault="False" proxyaddress="http://127.0.0.1:8888" bypassonlocal="True"   /&gt;
      &lt;/defaultProxy&gt;
    &lt;/system.net&gt;
  </code></pre>
  
  <p>Is there a way to supply a username and password to this proxy setting?</p>