public void doAction(string operation)
    {
        switch (operation)
        {
        case "Play":
            SceneManager.LoadScene(1);
            break;

        case "Display Difficulty":
            menuPanel.SetActive(false);
            difficultyPanel.SetActive(true);
            break;

        case "Display Controls":
            menuPanel.SetActive(false);
            controlsPanel.SetActive(true);
            break;

        case "Quit":
                        #if UNITY_EDITOR
            UnityEditor.EditorApplication.isPlaying = false;
                        #else
            Application.Quit();
                        #endif
            break;

        case "Easy Difficulty":
            difficultyLevel.setDifficulty(DifficultyType.EasyMode);
            break;

        case "Hard Difficulty":
            difficultyLevel.setDifficulty(DifficultyType.HardMode);
            break;

        case "Display Menu":
            if (difficultyPanel.activeSelf)
            {
                difficultyPanel.SetActive(false);
            }
            else
            {
                controlsPanel.SetActive(false);
            }

            menuPanel.SetActive(true);
            break;
        }
    }