Zip/Unzip using C#

I have spent few hours over internet to find out a way to create zip file using .net 2.0, C#. My intention was to avoid any third party library or application. I started with System.IO.Compression, but I did not find any resource about creating a zip from a directory with files and subdirectory as well. I got few .net library and I felt few of those are quite familier and using wiedly. But as I have some restriction i can not use those. Finally I got a solutoin to create and extract zip file using Shell32.dll. Here is two functions I wrote.

private static void ZipFile(string sourceFolder, string destinationFile)
{
byte[] emptyzip = new byte[] { 80, 75, 5, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

FileStream fs = File.Create(destinationFile);
fs.Write(emptyzip, 0, emptyzip.Length);
fs.Flush();
fs.Close();
fs = null;

//Copy a folder and its contents into the newly created zip file
Shell32.ShellClass sc = new Shell32.ShellClass();
Shell32.Folder SrcFlder = sc.NameSpace(sourceFolder);
Shell32.Folder DestFlder = sc.NameSpace(destinationFile);
Shell32.FolderItems items = SrcFlder.Items();
DestFlder.CopyHere(items, 20);
}


private static string UnzipFile(string inputFileName, string destinationPath)
{
if (!Directory.Exists(destinationPath))
Directory.CreateDirectory(destinationPath);

Shell shell = new ShellClass();
Folder sourceFolder = shell.NameSpace(inputFileName);
Folder destinationFolder = shell.NameSpace(destinationPath);
string outputFileName = sourceFolder.Items().Item(0).Name;
destinationFolder.CopyHere(sourceFolder.Items(), "");
return outputFileName;
}

Here is the code to call those function.

ZipFile(@"D:\SourceFolder", @"D:\MyZip.zip");

UnzipFile(@"D:\MyZip.zip", @"D:\ExtractFolder");

Hope this may help you. Thanks.