The request failed with HTTP status 401: Unauthoriz

private Assembly BuildAssemblyFromWSDL(Uri webServiceUri)
{
if (String.IsNullOrEmpty(webServiceUri.ToString()))
throw new Exception("Web Service Not Found");

//This following code does not work for NAV Web services so I replaced it
//XmlTextReader xmlreader = new XmlTextReader(webServiceUri.ToString() + "?wsdl");
// Start of new code -->
l_http = (HttpWebRequest)WebRequest.Create(webServiceUri.ToString());
_Credntial = new System.Net.NetworkCredential("Username", "password","Domain");

l_http.Timeout = 50000; // Timeout after 5 seconds

l_http.UseDefaultCredentials = false;
l_http.PreAuthenticate = true;
l_http.Credentials = _Credntial;
l_http.PreAuthenticate = true;

//l_http.GetResponse(
//l_http.UseDefaultCredentials = false;
//_Credntial = System.Net.CredentialCache.DefaultCredentials;


//PropertyInfo UseDefaultCred =


HttpWebResponse l_response = (HttpWebResponse)l_http.GetResponse();

Encoding enc = Encoding.GetEncoding(1252); // Windows default Code Page

StreamReader l_responseStream = new StreamReader(l_response.GetResponseStream(), enc);

XmlTextReader xmlreader = new XmlTextReader(l_responseStream);
// End of new code <--

ServiceDescriptionImporter descriptionImporter = BuildServiceDescriptionImporter(xmlreader);

return CompileAssembly(descriptionImporter);
}

public T InvokeMethod<T>( string serviceName, string methodName, params object[] args )
{
// create an instance of the specified service
// and invoke the method
Object obj = this.webServiceAssembly.CreateInstance(serviceName);
Type t1 = l_http.GetType();
Type type = obj.GetType();



// NAV Web services failed here because the service was not using default credentials
// Start of inserted code --->
// Try to tell it to useDefaultCredentials.
PropertyInfo UseDefaultCred = type.GetProperty("UseDefaultCredentials");
//PropertyInfo UseDefaultCred =
UseDefaultCred.SetValue(obj, true,null);

// End of inserted code <---

return (T)type.InvokeMember(methodName,BindingFlags.InvokeMethod,null, obj,args);
}