Valuta converter realtime

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Xml;

namespace E
{
    public class Program
    {
        private static IDictionary<string, XmlDocument> cache = new Dictionary<string, XmlDocument>();
        public static decimal GetRate(DateTime date, string currency)
        {
            if(currency == "DKK") return 100.00m;
            string datestr = date.ToString("yyyy-MM-dd");
            XmlDocument doc;
            if(cache.ContainsKey(datestr))
            {
                doc = cache[datestr];
            }
            else
            {
                doc = new XmlDocument();
                doc.Load("http://www.nationalbanken.dk/_vti_bin/DN/DataService.svc/CurrencyRatesHistoryXML?lang=da");
                cache[datestr] = doc;
            }
            XmlNamespaceManager xnm = new XmlNamespaceManager(doc.NameTable);
            xnm.AddNamespace("gesmes", "http://www.gesmes.org/xml/2002-08-01");
            xnm.AddNamespace("default", "http://www.ecb.int/vocabulary/2002-08-01/eurofxref");
            string ratestr = doc.SelectSingleNode("/gesmes:Envelope/default:Cube/default:Cube[@time='" + datestr + "']/default:Cube[@currency='" + currency + "']/@rate", xnm).Value;
            return decimal.Parse(ratestr,  new CultureInfo("da-DK", false));
        }
        public static decimal Convert(DateTime date, decimal amount, string fromcurrency, string tocurrency)
        {
            decimal fromrate = GetRate(date, fromcurrency);
            decimal torate = GetRate(date, tocurrency);
            return amount * fromrate / torate;
        }
        public static decimal Convert(decimal amount, string fromcurrency, string tocurrency) {
            return Convert(DateTime.Now, amount, fromcurrency, tocurrency);
        }
        public static void Main(string[] args)
        {
            Console.WriteLine(Convert(10.00m, "DKK", "EUR"));
            Console.WriteLine(Convert(10.00m, "DKK", "USD"));
            Console.ReadKey();
        }
    }
}

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Xml;

namespace E
{
    public class Program
    {
        private static IDictionary<string, XmlDocument> cache = new Dictionary<string, XmlDocument>();
        public static decimal GetRate(DateTime date, string currency)
        {
            if(currency == "DKK") return 100.00m;
            string datestr = date.ToString("yyyy-MM-dd");
            XmlDocument doc;
            if(cache.ContainsKey(datestr))
            {
                doc = cache[datestr];
            }
            else
            {
                doc = new XmlDocument();
                doc.Load("http://www.nationalbanken.dk/_vti_bin/DN/DataService.svc/CurrencyRatesHistoryXML?lang=da");
                cache[datestr] = doc;
            }
            XmlNamespaceManager xnm = new XmlNamespaceManager(doc.NameTable);
            xnm.AddNamespace("gesmes", "http://www.gesmes.org/xml/2002-08-01");
            xnm.AddNamespace("default", "http://www.ecb.int/vocabulary/2002-08-01/eurofxref");
            XmlNode rateinfo = doc.SelectSingleNode("/gesmes:Envelope/default:Cube/default:Cube[@time='" + datestr + "']/default:Cube[@currency='" + currency + "']/@rate", xnm);
            if(rateinfo != null)
            {
                // current file has info for this date => we use that info
                string ratestr = rateinfo.Value;
                return decimal.Parse(ratestr,  new CultureInfo("da-DK", false));
            }
            else
            {
                // current file has info for this date => we try previous day
                cache.Remove(datestr);
                Console.WriteLine("recurse");
                return GetRate(date.AddDays(-1), currency);
            }
        }
        public static decimal Convert(DateTime date, decimal amount, string fromcurrency, string tocurrency)
        {
            decimal fromrate = GetRate(date, fromcurrency);
            decimal torate = GetRate(date, tocurrency);
            return amount * fromrate / torate;
        }
        public static decimal Convert(decimal amount, string fromcurrency, string tocurrency) {
            return Convert(DateTime.Now, amount, fromcurrency, tocurrency);
        }
        public static void Main(string[] args)
        {
            Console.WriteLine(Convert(10.00m, "DKK", "EUR"));
            Console.WriteLine(Convert(10.00m, "DKK", "USD"));
            Console.ReadKey();
        }
    }
}