XML : Paste text from EditText to xml string

I have EditText field and WebClient.

In EditText user write city.

I need to place text from EditText to xml string.

Code of POST request with xml

  nadislati.Click += delegate          {                using (var client = new WebClient())              {                    var values  = new NameValueCollection();                  values["Order"] = "<Order \n CallConfirm=\"1\"\n PayMethod=\"Безнал\" \n QtyPerson=\"2\" \n Type=\"2\" \n PayStateID=\"0\" \n Remark=\"тестовый заказ с мобильного приложения. просьба при получении заказа переслать скриншот на имейл ....@\" \n RemarkMoney=\"0\" \n TimePlan=\"\" \n Brand=\"1\" \n DiscountPercent=\"0\" \n BonusAmount=\"0\"\n Department=\"\"\n >\n <Customer Login=\"suhomlineugene@gmail.com\" FIO=\"Evgenyi Sukhomlin\"/>\n <Address \n CityName=\"\" \n StationName=\"\" \n StreetName=\"\" \n House=\"\" \n Corpus=\"\" \n Building=\"\" \n Flat=\"\" \n Porch=\"\" \n Floor=\"\" \n DoorCode=\"\"\n />\n\n <Phone Code=\" 096\" Number=\"50 526-43-19\" />\n <Products>\n <Product Code=\"574\" Qty=\"1\" />\n </Products>\n </Order>";                  values["OrderText"] = "hello";                  var response  = client.UploadValues("http://193.203.48.54:5000/fastoperator.asmx/AddOrder", values);                    var responseString = Encoding.UTF8.GetString(response);                 }                Vibrator vib = (Vibrator)this.GetSystemService(Context.VibratorService);              vib.Vibrate(30);              var intent31 = new Intent(this, typeof(Cart3Activity));                  StartActivity(intent31);          };    

How I can realize this?