Show selected guideline indices

        void ShowSelectedGuidelines()
        {
            string selectedGuidelines = "";
            if (selectedGuidelineIndices.Count > 0)
            {
                selectedGuidelines = "Selected Guidelines:\n\n";
                if (selectedGuidelineIndices.Count < levelGuidelines.Count)
                {
                    int lastShownIndex = -2;
                    int lastIndexInCombo = -2;
                    for (int i = 0; i < selectedGuidelineIndices.Count; i++)
                    {
                        if (lastShownIndex == -2)
                        {
                            selectedGuidelines += (selectedGuidelineIndices[i] + 1).ToString();
                            if (i < selectedGuidelineIndices.Count - 1)
                                selectedGuidelines += ", ";
                        }
                        if (selectedGuidelineIndices[i] > lastIndexInCombo + 1)
                        {
                            if (lastIndexInCombo >= 0)
                            {
                                selectedGuidelines += (selectedGuidelineIndices[i] + 1).ToString();
                                if (i < selectedGuidelineIndices.Count - 1)
                                    selectedGuidelines += ", ";
                            }
                            lastIndexInCombo = lastShownIndex = selectedGuidelineIndices[i];
                        }
                        else if (selectedGuidelineIndices[i] == lastIndexInCombo + 1)
                        {
                            if (lastShownIndex == lastIndexInCombo)
                                selectedGuidelines += (selectedGuidelineIndices[i] + 1).ToString() + "-";
                            if (lastShownIndex >= 0)
                                lastIndexInCombo = selectedGuidelineIndices[i];
                            if (i == selectedGuidelineIndices.Count - 1)
                                selectedGuidelines += (selectedGuidelineIndices[i] + 1).ToString();
                        }
                    }
                }
                else if (selectedGuidelineIndices.Count == levelGuidelines.Count)
                    selectedGuidelines = "Selected Guidelines: All";
            }
            else
                selectedGuidelines = "No guidelines selected.";
            toolTip1.SetToolTip(groupBox4, selectedGuidelines);
        }