void LoadHiScore()
    {
        if (File.Exists(Application.persistentDataPath + "/" + "gradius.sav"))
        {
            FileStream      fs = File.Open(Application.persistentDataPath + "/" + "gradius.sav", FileMode.Open);
            BinaryFormatter bf = new BinaryFormatter();

            GradiusSave sav = (GradiusSave)bf.Deserialize(fs);
            hiscore = sav.hiscore;
            UIManager.instance.OnHiScoreChanged(hiscore);
        }
    }
    void loadHighScore()
    {
        if (File.Exists(Application.persistentDataPath + "/" + "gradius.sav"))
        {
            FileStream      fs = File.Open(Application.persistentDataPath + "/" + "gradius.sav", FileMode.Open);
            BinaryFormatter bf = new BinaryFormatter();

            GradiusSave sav = (GradiusSave)bf.Deserialize(fs);
            highscore = sav.hiscore;

            fs.Close();
        }
    }
    void SaveHiScore()
    {
        GradiusSave save = new GradiusSave();

        save.hiscore = hiscore;

        FileStream fs = File.Create(Application.persistentDataPath + "/" + "gradius.sav");

        BinaryFormatter bf = new BinaryFormatter();

        bf.Serialize(fs, save);

        fs.Close();
    }