How to compress directory, Make RAR file in c#

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.IO.Compression;


namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            string sFileToZip = @"C:\Documents and Settings\My Documents\Visual Studio 2008\Projects\ConsoleApplication1\bin\Debug\Stuff\text1.txt";
            string sZipFile = @"C:\Documents and Settings\My Documents\Visual Studio 2008\Projects\ConsoleApplication1\bin\Debug\Stuff\text1.zip";

            using (FileStream __fStream = File.Open(sZipFile, FileMode.Create))
            {
                GZipStream obj = new GZipStream(__fStream, CompressionMode.Compress);

                byte[] bt = File.ReadAllBytes(sFileToZip);
                obj.Write(bt, 0, bt.Length);

                obj.Close();
                obj.Dispose();
            }
        }
    }
}