public static bool UploadUniqueFileOnServer (Uri serverUri, string fileName)
{
    // The URI described by serverUri should use the ftp:// scheme.
    // It contains the name of the directory on the server.
    // Example: ftp://contoso.com.
    // 
    // The fileName parameter identifies the file containing the data to be uploaded.

    if (serverUri.Scheme != Uri.UriSchemeFtp)
    {
        return false;
    }
    // Get the object used to communicate with the server.
    FtpWebRequest request = (FtpWebRequest)WebRequest.Create(serverUri);
    request.Method = WebRequestMethods.Ftp.UploadFileWithUniqueName;
    // Set a time limit for the operation to complete.
    request.Timeout = 600000;
    
    // Copy the file contents to the request stream.
    const int bufferLength = 2048;
    byte[] buffer = new byte[bufferLength];
    int count = 0;
    int readBytes = 0;
    FileStream stream = File.OpenRead(fileName);
    Stream requestStream = request.GetRequestStream();
    do
    {
        readBytes = stream.Read(buffer, 0, bufferLength);
        requestStream.Write(buffer, 0, bufferLength);
        count += readBytes;
    }
    while (readBytes != 0);
    
    Console.WriteLine ("Writing {0} bytes to the stream.", count);
    // IMPORTANT: Close the request stream before sending the request.
    requestStream.Close();
    FtpWebResponse response = (FtpWebResponse) request.GetResponse();
    Console.WriteLine("Upload status: {0}, {1}",response.StatusCode, response.StatusDescription);         
    Console.WriteLine ("File name: {0}", response.ResponseUri);
    response.Close();
    return true;
}