searching for available domain name in asp.net

string sld = txtsearch.Text.Trim();
          // URL for API request
           const string url = "https://kats.supersite.myorderbox.com/api/domains/available.json?api-key=000000000000000&password=00000000$$&domain-name=domain1&tlds=com";

          // Load the API results into an XmlDocument object
          var xmlDoc = new XmlDocument();
          //const string url2 = url.Replace("&", "&");
          xmlDoc.Load(url);

          // Read the results
          var rrpCode = xmlDoc.SelectSingleNode("/interface-response/RRPCode").InnerText;
          var rrpText = xmlDoc.SelectSingleNode("/interface-response/RRPText").InnerText;

          // Perform actions based on results
          switch (rrpCode)
          {
              case "210":
                  Console.WriteLine("Domain available");
                  break;
              case "211":
                  Console.WriteLine("Domain not available");


                  break;
              default:
                  Console.WriteLine("{0} {1}", rrpCode, rrpText);
                  break;
          }

          Console.Read();