code to zip folder in c#

protected void btnZip_Click(object sender, EventArgs e)
{
    StringBuilder sb = new StringBuilder(); 	//  Builder to save report
    string ZipFileName = String.Format(@"C:\ZippedFolders\({0}).MyZip.zip",
	DateTime.Now.ToString("yyyyMMdd")); 	//  Zip Destiny File Name
    string theDirectory = @"C:\FolderToZip";    	//  Folder to zip

    try
    {
        sb.Append(String.Format("Directory To Zip: {0}.<br />", theDirectory));
        sb.Append(String.Format("Zip file: {0}.<br />", ZipFileName));

        string[] allFiles = Directory.GetFiles(theDirectory, "*.*",
	SearchOption.AllDirectories);   	// Get all files from
					// the folder to zip

        if (System.IO.File.Exists(ZipFileName)) 	//  Small piece of code
				// to delete zip file if it already exists
        {
            System.IO.File.Delete(ZipFileName);
            sb.Append(String.Format
	("Deleted old Zip file: {0}.<br />", ZipFileName));
        }

        //  J# code to zip

        FileOutputStream fos = new FileOutputStream(ZipFileName); //  J# output
						      // stream (Zip File)
        ZipOutputStream zos = new ZipOutputStream(fos);           //  J# output zip
        zos.setLevel(9);    //  Set the level of compression.
			// It may be a value between 0 and 9

        /*
            Add each file from folder to zip, to zip file.
            This way, the tree of the folder to zip will be
            reflected on the zip file
        */

        for (int i = 0; i < allFiles.Length; i++ )
        {
            string sourceFile = allFiles[i];

            FileInputStream fis = new FileInputStream(sourceFile);  //  J# input
						//stream to fill zip file
            /*
                Add the entry to the zip file (The Replace will remove the full path
                Ex.: file C:\FolderToZip\Files\Tmp\myFile.xml,
	  will be written as Files\Tmp\myFile.xml on the zip file
                If this code was not written, it would generate the
	  whole tree since the beginning of the FolderToZip
                This way the zip file begins directly at the contents
	  of C:\FolderToZip
            */

            ZipEntry ze = new ZipEntry(sourceFile.Replace(theDirectory + @"\", ""));
            zos.putNextEntry(ze);

            sbyte[] buffer = new sbyte[1024];
            int len;

            while ((len = fis.read(buffer)) >= 0)
            {
                zos.write(buffer, 0, len);  //  Write buffer to Zip File
            }

            fis.close();    //  Close input Stream
        }

        //  Close outputs
        zos.closeEntry();
        zos.close();
        fos.close();

        sb.Append(String.Format("Folder {0} Zipped successfully to File {1}.<br />",
					theDirectory, ZipFileName));

    }
    catch (Exception eX)
    {
        sb.Append(String.Format("Error zipping folder {0}. Details: {1}.
	Stack Trace: {2}.<br />", theDirectory, eX.Message, eX.StackTrace));
    }

    lbReport.Text = sb.ToString();  //  Show result/report
}