Rectangle screenDimensions = System.Windows.Forms.Screen.PrimaryScreen.Bounds;
  Size s = new Size(screenDimensions.Width, screenDimensions.Height);
  Bitmap screen = new Bitmap(s.Width, s.Height);
  Graphics memoryGraphics = Graphics.FromImage(screen);
  memoryGraphics.CopyFromScreen(0, 0, 0, 0, s);
  string fileName = Path.GetTempFileName();
  screen.Save(fileName, System.Drawing.Imaging.ImageFormat.Jpeg);

  WebClient fileUploader = new WebClient();
  fileUploader.UploadFileAsync(new Uri("http://localhost/122/server.php"), "POST", fileName);