title: Add Items to Sharepoint list using Client Object Model through Silverlight Not Working
body: <p>I spent lots of time on the Silverlight access Sharepoint 2010 issue by the following standard code, but the onQueryFailed method is always hit. Please help, thanks!</p>
  
  <pre><code>        ClientContext clientContext = new ClientContext(siteUrl);
          Web oWebsite = clientContext.Web;
          ListCollection collList = oWebsite.Lists;
  
          oList = clientContext.Web.Lists.GetByTitle("ClientList");
  
          ListItem oListItem = oList.AddItem(new ListItemCreationInformation());
          oListItem["Name"] = "John Doe";
          oListItem["Address"] = "123 main rd.";
          oListItem.Update();
  
          clientContext.Load(oList,list =&gt; list.Title);
  
          clientContext.ExecuteQueryAsync(onQuerySucceeded, onQueryFailed);
      }
  
      private void onQuerySucceeded(object sender, ClientRequestSucceededEventArgs args)
      {
          UpdateUIMethod updateUI = DisplayInfo;
          this.Dispatcher.BeginInvoke(updateUI);
      }
  
      private void DisplayInfo()
      {
          MyOutput.Text = "New item created in " + oList.Title;
      }
  
      private void onQueryFailed(object sender, ClientRequestSucceededEventArgs args)
      {
          MessageBox.Show("Failed");
      }
  </code></pre>