private void client_DownloadProgressChanged (object sender, DownloadProgressChangedEventArgs e)
{
double bytesIn = double.Parse (e.BytesReceived.ToString());
double totalBytes = double.Parse (e.TotalBytesToReceive.ToString());
double percentage = bytesIn / totalBytes * 100;
_progressBar.Value = int.Parse (Math.Truncate (percentage).ToString());
}