function dyncat(h, t, titre) {
	var h2 = document.getElementsByTagName("h2")[h];
	var table = document.getElementsByTagName("table")[t];
	
	if (table.style.display=='none') {
		table.style.display=''; 
		h2.getElementsByTagName("span")[0].innerHTML = titre;
		pref[t] = 1;
	} else {
		table.style.display='none';
		h2.getElementsByTagName("span")[0].innerHTML = titre;
		pref[t] = 0;
	}
}