title: HTTP status 407: Proxy authentication required Error when calling web service
body: <p>I have spent two hours on this error "HTTP status 407: Proxy authentication required Error " when calling a web service, my code is like following</p>
  
  <pre><code>WebProxy oWebProxy = new System.Net.WebProxy(ProxyServer, ProxyPort);
  oWebProxy.Credentials = new NetworkCredential(ProxyUser,ProxyPassword,ProxyDomain);
  oserv.Proxy = oWebProxy;
  oserv.Credentials = new NetworkCredential(theusername, thepassword);
  </code></pre>
  
  <p>I have verified that the proxy address, user id password are all correct, and I could access the web service thru the IE in same pc, but when I run the code with VS, the error keeps popup.
  I have tried the <code>UserDefaultCredentials=true</code> as well, but no luck.</p>
  
  <p>Any idea?</p>