function show_album_change_image (i) {
    var el = show_album_links[i];
    show_album_show_page(el);
}

function show_album_show_page (el) {
    var page = el;
    while (page.tagName != 'DIV') {
        page = page.parentNode;
        if (!page) return;
    }
    var n = page.previousSibling;
    while (n) {
        if (n.tagName == 'DIV')
            n.style.display = 'none';
        n = n.previousSibling;
    }
    var n = page.nextSibling;
    while (n) {
        if (n.tagName == 'DIV')
            n.style.display = 'none';
        n = n.nextSibling;
    }
    page.style.display = '';
    if (el.tagName == 'A')
        el.focus();
    var pageNumber = page.id.substr(4) - 0;
    var pageNumber_el = document.getElementById('pageNumber');
    if (pageNumber_el) {
        pageNumber_el.innerHTML = pageNumber;
        var prev_el = document.getElementById('previousPage');
        prev_el.href = '?page=' + (pageNumber - 1);
        prev_el.style.visibility = pageNumber == 1 ? "hidden" : "";
        var next_el = document.getElementById('nextPage');
        next_el.href = '?page=' + (pageNumber + 1);
        next_el.style.visibility = document.getElementById('page'+(pageNumber+1)) ? "" : "hidden";
    }
}

function show_album_next_page() {
    var pageNumber = document.getElementById('pageNumber').innerHTML;
    var page = document.getElementById('page'+(pageNumber-0+1));
    if (page) show_album_show_page(page);
}

function show_album_previous_page() {
    var pageNumber = document.getElementById('pageNumber').innerHTML;
    var page = document.getElementById('page'+(pageNumber-1));
    if (page) show_album_show_page(page);
}

var show_album_links = [];
function show_album_link_mapper (el) {
    var hr = el.href;
    var title = el.title;
    if (title == null) title = el.alt;
    show_album_links[show_album_links.length] = el;
    return [hr.replace('pages/', 'images/').replace('.html', '.jpg').replace('.htm', '.jpg'), el.title];
}

function show_album_get_link_mapper () {
    show_album_links = [];
    return show_album_link_mapper;
}