how to read zipped folder in windows phone 7

public MainPage()
{
InitializeComponent();
Uri uri = new Uri("OnlineTv;component/example.zip", UriKind.Relative);

// Download the zip package.
WebClient webClient = new WebClient();
webClient.OpenReadAsync(uri);
webClient.OpenReadCompleted += new OpenReadCompletedEventHandler(webClient_OpenReadCompleted);


}
void webClient_OpenReadCompleted(object sender,
OpenReadCompletedEventArgs e)
{
// Extract the desired image from the zip package.
Stream zipPackageStream = e.Result;
Image image = LoadImageFromZipPackage(
"Tulips.jpg", zipPackageStream);
this.stackPanel.Children.Add(image);
}

public Image LoadImageFromZipPackage(
string relativeUriString, Stream zipPackageStream)
{
// Get the image stream at the specified URI that
// is relative to the application package root.
Uri uri = new Uri(relativeUriString, UriKind.Relative);
StreamResourceInfo zipPackageSri =
new StreamResourceInfo(zipPackageStream, null);
StreamResourceInfo imageSri =
Application.GetResourceStream(zipPackageSri, uri);

// Convert the stream to an Image.
BitmapImage bi = new BitmapImage();
bi.SetSource(imageSri.Stream);
Image img = new Image();
img.Source = bi;

return img;
}



Stream zipPackageStream = e.Result;
here I m getting error An exception occurred during a WebClient request
system.net.webexception