I want to pack to zip some folder using SharpZipLib. Example stucture

```
directory1:
    directory2:
         file1
    file2
    directory3:
        directory4:

```

When I pack it using c# code from here:

<http://wiki.sharpdevelop.net/SharpZipLib-Zip-Samples.ashx#Create_a_Zip_with_full_control_over_contents_0>

I get zip archives without `directory3` and `directory4`.

My question is how can I pack to get archives with `directory3` and `directory4`.