public IEnumerator UnlockedTimer()
    {
        if (!unlocked)
        {
            unlocked = true;
            if (haveWeapon1 == HaveWeapon.M4A1 && M4A1.unlockedLevel < 10 && unlockedScore * (M4A1.unlockedLevel + 1) <= gameManager.Score)
            {
                M4A1.unlockedLevel++;
                gameManager.Score -= unlockedScore * M4A1.unlockedLevel;
                M4A1.WeaponManager();
                audioSource.PlayOneShot(upgradeSound);
            }
            if (haveWeapon1 == HaveWeapon.LMG && LMG.unlockedLevel < 10 && unlockedScore * (LMG.unlockedLevel + 1) <= gameManager.Score)
            {
                LMG.unlockedLevel++;
                gameManager.Score -= unlockedScore * LMG.unlockedLevel;
                LMG.WeaponManager();
                audioSource.PlayOneShot(upgradeSound);
            }
            if (haveWeapon1 == HaveWeapon.HandGun && HandGun.unlockedLevel < 10 && unlockedScore * (HandGun.unlockedLevel + 1) <= gameManager.Score)
            {
                HandGun.unlockedLevel++;
                gameManager.Score -= unlockedScore * HandGun.unlockedLevel;
                HandGun.WeaponManager();
                audioSource.PlayOneShot(upgradeSound);
            }
            yield return(new WaitForSeconds(unlockedInterval));

            unlocked = false;
        }
    }