Bit.ly URL shortening

bitly.cs

using System.Configuration;
using System.IO;
using System.Net;
using System.Text;
using System.Xml;

namespace MyApp
{
    public class Bitly
    {
        public static string Shorten(string url)
        {
            return Shorten(
                ConfigurationManager.AppSettings["bitlyUsername"],
                ConfigurationManager.AppSettings["bitlyAPIKey"],
                url,
                "Shorten");
        }

        private static string Shorten(string username, string apiKey, string input, string type)
        {
            string Btype;
            string Xtype;
            string Itype;

            switch (type)
            {
                case "Shorten":
                    Btype = "shorten";
                    Xtype = "shortUrl";
                    Itype = "longUrl";
                    break;
                case "MetaH":
                    Btype = "info";
                    Xtype = "htmlMetaDescription";
                    Itype = "hash";
                    break;
                case "MetaU":
                    Btype = "info";
                    Xtype = "htmlMetaDescription";
                    Itype = "shortUrl";
                    break;
                case "ExpandH":
                    Btype = "expand";
                    Xtype = "longUrl";
                    Itype = "hash";
                    break;
                case "ExpandU":
                    Btype = "expand";
                    Xtype = "longUrl";
                    Itype = "shortUrl";
                    break;
                case "ClicksU":
                    Btype = "stats";
                    Xtype = "clicks";
                    Itype = "shortUrl";
                    break;
                case "ClicksH":
                    Btype = "stats";
                    Xtype = "clicks";
                    Itype = "hash";
                    break;
                case "UserU":
                    Btype = "info";
                    Xtype = "shortenedByUser";
                    Itype = "shortUrl";
                    break;
                case "UserH":
                    Btype = "info";
                    Xtype = "shortenedByUser";
                    Itype = "hash";
                    break;
                default:
                    return "";
            }

            var url = new StringBuilder();              //Build a new string
            url.Append("http://api.bit.ly/");           //Add base URL
            url.Append(Btype);
            url.Append("?version=2.0.1");               //Add Version
            url.Append("&format=xml");
            url.Append("&");
            url.Append(Itype);
            url.Append("=");
            url.Append(input);                          //Append longUrl from input
            url.Append("&login=");                      //Add login "Key"
            url.Append(username);                       //Append login from input
            url.Append("&apiKey=");                     //Add ApiKey "Key"
            url.Append(apiKey);                         //Append ApiKey from input
            var request = WebRequest.Create(url.ToString()); //prepare web request
            var responseStream = new StreamReader(request.GetResponse().GetResponseStream()); //prepare responese holder
            var response = responseStream.ReadToEnd();  //fill up response
            responseStream.Close();                     //Close stream

            var data = response; //Turn it into a string
            var newdata = XmlParseGeneral(data, Xtype); //parse the XML

            return newdata == "Error" ? string.Empty : newdata;
        }

        private static string XmlParseGeneral(string url, string type)    //XML parse Function
        {
            var xmlrt1 = new XmlTextReader(new StringReader(url));

            while (xmlrt1.Read())
            {
                string strNodeType = xmlrt1.NodeType.ToString();
                string strName = xmlrt1.Name;

                if (strNodeType != "Element" || strName != type) continue;
                xmlrt1.Read();

                return xmlrt1.Value; //Return output
            } return "";// end while
        }
    }
}