JsonHelper for Silverlight

using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.Json;
using System.Reflection;
using System.Collections;

namespace Json
{
    public static class JsonHelper
    {
        public static T ParseObject<T>(JsonValue jsonObject)
        {
            T result = (T) Activator.CreateInstance(typeof(T));

            foreach (PropertyInfo pi in result.GetType().GetProperties())
            {
                if (jsonObject.ContainsKey(pi.Name))
                {
                    JsonValue jsonPrimitive = jsonObject[pi.Name];
                    if (pi.PropertyType != typeof(DateTime))
                    {
                        object o = Convert.ChangeType(jsonPrimitive.ToString(), pi.PropertyType, new FakeFormatProvider());
                        if (o is string)
                        {
                            o = (o as string).Replace("\"", "");
                        }
                        pi.SetValue(result, o, null);
                    }
                  
                }
            }

            return result;
        }

        public static string ToJson(this object obj)
        {
            string result = "";

            if (obj is IList)
            {
                result = "[";
                IList objList = (IList)obj;


                for (int i = 0; i < objList.Count; i++)
                {
                    result += objList[i].ToJson().ToString();

                    if (i != objList.Count -1)
                    {
                        result += ",";
                    }
                }

                result += "]";
            }
            else if (obj is int || obj is Int32 || obj is Int16 || obj is Int64)
            {
                result = obj.ToString();
            }
            else if (obj is string)
            {
                result = "\"" + obj.ToString() + "\"";
            }
            else
            {
                result = "{";

                for (int i = 0; i < obj.GetType().GetProperties().Length; i++)
                {
                    PropertyInfo pi = obj.GetType().GetProperties()[i];
                    result += "\"" + pi.Name + "\":" + pi.GetValue(obj, null).ToJson();
                    if (i != obj.GetType().GetProperties().Length - 1)
                    {
                        result += ",";
                    }
                }

                result += "}";
            }

            return result;
        }

    }

    public class FakeFormatProvider : IFormatProvider
    {
        public object GetFormat(Type formatType)
        {
            return null;
        }
    }

}