// write out the screenshot

                    string screenshotDir = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);

                    string filename = FileUtils.FindNumberedFile("DesertPaintLab_Colormatch", "png", screenshotDir);

                    int x = swatchX - 16;

                    int captureAreaWidth = ReactionRecorder.Instance.ColorBarWidth + 32;

                    captureAreaWidth = Math.Min(screenWidth - x, captureAreaWidth);

                    int y = swatchY - 16;

                    int captureAreaHeight = ReactionRecorder.Instance.BlueBarSpacing + 42;

                    captureAreaHeight = Math.Min(screenHeight - y, captureAreaHeight);

                    Gdk.Pixbuf outPixBuf = new Gdk.Pixbuf(screenBuffer, Math.Max(0, x), Math.Max(0, y), 

                        captureAreaWidth, captureAreaHeight);

                    //Gdk.Pixbuf outPixBuf = new Gdk.Pixbuf(screenBuffer, Math.Max(0, redPixelStartX), Math.Max(0, redPixelStartY),

                    //    ReactionRecorder.Instance.ColorBarWidth, ReactionRecorder.Instance.GreenBarSpacing - ReactionRecorder.Instance.RedBarSpacing);

                    //screenBuffer.Save(filename, "png");

                    outPixBuf.Save(filename, "png");

                }

            }

            //screenBuffer.Save("screenshot.png", "png");

            if (isCaptured)

            {

                string warning = "";

                if (reactedColor.Red == 0)

                {

                    warning = warning + "\nRed is too low.";

                }

                if (reactedColor.Green == 0)

                {

                    warning = warning + "\nGreen is too low.";

                }

                if (reactedColor.Blue == 0)

                {

                    warning = warning + "\nBlue is too low.";

                }

                if (reactedColor.Red == 255)

                {

                    warning = warning + "\nRed is too high.";

                }

                if (reactedColor.Green == 255)

                {

                    warning = warning + "\nGreen is too high.";

                }

                if (reactedColor.Blue == 255)

                {

                    warning = warning + "\nBlue is too high.";

                }

                if (warning.Length != 0)

                {

                    isCaptured = true;

                    Gtk.MessageDialog md = new Gtk.MessageDialog((Gtk.Window)Toplevel,

                    Gtk.DialogFlags.DestroyWithParent,

                    Gtk.MessageType.Error, Gtk.ButtonsType.Ok,

                    "Reaction clipped.  You will need to do a " +

                    "3-way reaction to test this pair.  Details: " +

                    warning);

                    md.Run();

                    md.Destroy();

                }

                else

                {

                    recordButton.Sensitive = recordEnabled;

                }

                captureButton.Sensitive = false;

            }

            else

            {

                Gtk.MessageDialog md = new Gtk.MessageDialog((Gtk.Window)Toplevel,

                    Gtk.DialogFlags.DestroyWithParent,

                    Gtk.MessageType.Error, Gtk.ButtonsType.Ok,

                    "Pigment Lab dialog box NOT FOUND.  Please ensure " +

                    "that there is an unobstructed view of the dialog " +

                    "and that your interface size is set to 'small' " +

                    "when you press the Capture button.");

                md.Run();

                md.Destroy();

            }

            progressBar.Hide();

            recordButton.Show();

            ingredient1ComboBox.Sensitive = true;

            ingredient2ComboBox.Sensitive = true;

            ingredient3ComboBox.Sensitive = false;

            UpdateIngredients();

        }

        private void NotifyCaptureComplete()

        {

            OnCaptureComplete(

                ReactionRecorder.Instance.IsCaptured,

                ReactionRecorder.Instance.RecordedColor,

                ReactionRecorder.Instance.SwatchX,

                ReactionRecorder.Instance.SwatchY);

        }

        unsafe void CaptureReactionColor()

        {

            // Take a screenshot.

            int screenWidth, screenHeight;

            Gdk.Window rootWindow = Gdk.Global.DefaultRootWindow;

            DesertPaintLab.AppSettings.Get("ScreenWidth", out screenWidth);

            DesertPaintLab.AppSettings.Get("ScreenHeight", out screenHeight);

            Gdk.Image rootImage = rootWindow.GetImage(0, 0, screenWidth, screenHeight);

            screenBuffer.GetFromImage(rootImage, rootImage.Colormap, 0, 0, 0, 0, screenWidth, screenHeight);

            rootImage.Unref();

            System.GC.Collect(); // really, clean up now