function spoil(spoiler) {
    var div = spoiler.parentNode.parentNode.getElementsByTagName('div')[1];
    if (div.style.display != 'none') {
        div.style.display = 'none';
        spoiler.innerHTML = 'Spoil me!'
    } else {
        div.style.display = 'block';
        spoiler.innerHTML = 'Stop it!'
    }
}