function afficheNav(idNav, open_it) {
	var objNav = document.getElementById(idNav);
	if (objNav == null) return;
	var objImg = document.getElementById('img_'+idNav);
	var isClosed = (objNav.style.display=='none');
	if (open_it == null)
		newState = isClosed;
	else
		newState = open_it;
	//alert(objNav.style.display+' - ');
	if (isClosed) {
		if (newState) {
			// SEB use display='' restore initial state, instead of 'block' wich is not correct
			objNav.style.display='';
			//objImg.src='/images/arbre/minus.gif';
			//alert("open : "+objImg.src);
			saveOpenState( idNav, true);
		}
	} else {
		if (!newState) {
			objNav.style.display='none';
			//objImg.src='/images/arbre/plus.gif';
			//alert("close : "+objImg.src);
			saveOpenState( idNav, false);
		}
	}
	return false;
}
function saveOpenState(idNav, opened) {
	if (navigator.my_save_states == null)
		navigator.my_save_states = new Array();
	if (opened) {
		navigator.my_save_states[idNav] = true;
		// str = ''; for (i in navigator.my_save_states) str += i + ' '; window.alert( str);
	}
	else
		delete( navigator.my_save_states[idNav]);
}