function page(p) {
    var page  = document.getElementById('page' + p);
    if (page != null) {
        page.style.display = 'block';
        hideallexcept(p);

        document.getElementById('gotopage' + p).style.color  = '#ff3399';
    }
}

function hideallexcept(p) {
    for (var i = 0; i <= 30; i++) {
        var page = document.getElementById('page' + i);
        if (page != null && p != i) {
            page.style.display = 'none';
            document.getElementById('gotopage' + i).style.color = '#000000';
        }
    }
}