title: IAsyncResult returned from Begin method is null?
body: <p>I need to return null if i get some error. But this throws,</p>
  
  <pre><code>IAsyncResult returned from Begin method is null.
  </code></pre>
  
  <p>Here is my code?</p>
  
  <pre><code>        try
          {
              var url = (string)state;
              var request = (HttpWebRequest)WebRequest.Create(url);
              return request.BeginGetResponse(cb, request);
          }
          catch (Exception ex)
          { 
          }
          return null;
  </code></pre>
  
  <p>How to return empty IAsyncResult?</p>