// apparition/disparition du formulaire d'abonnement
function postComment (tag, form) {
	tag.firstChild.style.background = (form.style.display == "block") ? "url(images/fleche.gif) no-repeat left top" : "url(images/fleche.gif) no-repeat left bottom";
	form.style.display = (form.style.display == "block") ? "none" : "block";
}