Turning journal pages through a list

I can currently flip back and forth between the first two pages by button click, but I have about 10 pages and don’t know how to continue from here. Any advice is appreciated!

public void Next()
{
    contents[0].SetActive(false);
    contents[1].SetActive(true);
    Debug.Log("Next page");
}

public void Previous()
{
    contents[0].SetActive(true);
    contents[1].SetActive(false);
    Debug.Log("Previous page");
}

pages[activePage]

onclick :

activePage++;
if (activePage) > pages.Length)
{
    oldPage = activePage
    activePage = 0;
}
pages[oldPage].SetActive(false)
pages[activePage].SetActive(true)

… and so on