C# Screen Shot whats in the pael

// The size of the browser window when we want to take the screenshot (and the size of the resulting bitmap)
  Bitmap bitmap = new Bitmap(MainPicturebox.Width, MainPicturebox.Height);
  Rectangle bitmapRect = new Rectangle(0, 0, MainPicturebox.Width, MainPicturebox.Height);
  // This is a method of the panel control, and the most important part
  panel1.DrawToBitmap(bitmap, bitmapRect);

  // Generate a thumbnail of the screenshot (optional)
  System.Drawing.Image origImage = bitmap;
  System.Drawing.Image origThumbnail = new Bitmap(120, 90, origImage.PixelFormat);

  Graphics oGraphic = Graphics.FromImage(origThumbnail);
  oGraphic.CompositingQuality = CompositingQuality.HighQuality;
  oGraphic.SmoothingMode = SmoothingMode.HighQuality;
  oGraphic.InterpolationMode = InterpolationMode.HighQualityBicubic;
  Rectangle oRectangle = new Rectangle(0, 0, 120, 90);
  oGraphic.DrawImage(origImage, oRectangle);

  // Save the file in PNG format
  origImage.Save("Screenshot.png", ImageFormat.Png);
  origImage.Dispose();