function spoil(elem) {
	var child = elem.getElementsByTagName('div');
	if(child[1].style.display == 'block') {
		child[0].innerHTML = 'Afficher ce message';
		child[1].style.display = 'none';
	} else {
		child[0].innerHTML = 'Masquer ce message';
		child[1].style.display = 'block';
	}
}