ShopManager.prevPage C# (CSharp) Method

    public void prevPage()
    {
        if (currentPage == 1)
        {
            page1.SetActive(false);
            page3.SetActive(true);
            currentPage = 3;
        }
        else
        if (currentPage == 2)
        {
            page2.SetActive(false);
            page1.SetActive(true);
            currentPage = 1;
        }
        else
        if (currentPage == 3)
        {
            page3.SetActive(false);
            page2.SetActive(true);
            currentPage = 2;
        }
    }