public void AddUpgrade(Button[] tab, Vector4[] cornerTab, GameObject toInstantiate)
    {
        Button toInstantiateButton;

        for (int i = 0; i < tab.Length; i++)
        {
            toInstantiateButton = tab [i];
            if ((i == 0 && !gm.HaveNoGuard()) || (i == 1 && !gm.HaveAllGuards()))
            {
                Button instance = ui.CreateInstance(toInstantiateButton.gameObject, new Vector2(cornerTab [i].x, cornerTab [i].y), new Vector2(cornerTab [i].z, cornerTab [i].w));
                ui.TextMenu(toInstantiateButton.name, new Vector2(1f, 1f), new Vector2(0f, 0f), instance.gameObject, new Color(0, 0, 0));
                if (i == 0)
                {
                    instance.onClick.AddListener(ButtonLife);
                }
                else
                {
                    instance.onClick.AddListener(ButtonGuard);
                }
                instance.transform.SetParent(toInstantiate.transform);
            }
        }
    }