function turnOn(id) {
	document.getElementById('menu_' + id + 'l').className = "highlightMenuLeft";
	document.getElementById('menu_' + id).className = "highlightMenu";
	document.getElementById('menu_' + id + 'r').className = "highlightMenuRight";
	return;
}
function turnBack(id) {
	document.getElementById('menu_' + id + 'l').className = "activeMenuLeft";
	document.getElementById('menu_' + id).className = "activeMenu";
	document.getElementById('menu_' + id + 'r').className = "activeMenuRight";
	return;
}
function turnOff(id) {
	document.getElementById('menu_' + id + 'l').className = "inactiveMenuLeft";
	document.getElementById('menu_' + id).className = "inactiveMenu";
	document.getElementById('menu_' + id + 'r').className = "inactiveMenuRight";
	return;
}

function setImage(index) {
	// on affiche l'image correcte
	document.getElementById('image_container').className = "image" + index;
	// on passe tous les boutons à éteint, sauf le bouton actif
	for (var i=1 ; i < 8 ; i++) {
		if (i == index)
			document.getElementById("image_tn_" + i).src = "/media/wbox.gif";
		else
			document.getElementById("image_tn_" + i).src = "/media/bbox.gif";
	}
}
function preloadImages(nb) {
	for (var i=1 ; i <= nb ; i++) {
		var img = new Image(345,230);
		img.src = "/media/image" + i + ".png";
	}
	var fond1 = new Image(1000,700);
	fond1.src = "/media/fond_domaine.jpg";
	var fond2 = new Image(1000,700);
	fond2.src = "/media/fond_valeur.jpg";
	var fond3 = new Image(1000,700);
	fond3.src = "/media/fond_contact.jpg";
	var photo1 = new Image(179,157);
	photo1.src = "/media/glb.png";
	var photo2 = new Image(179,157);
	photo2.src = "/media/mca.png";
	var photo3 = new Image(179,157);
	photo3.src = "/media/dal.png";
}
function updateImage(force) {
	if (force) {
		setImage(force);
	    setTimeout("updateImage()",7000);
	} else {
		var indx = document.getElementById('image_container').className;
		indx = indx.substring(5,indx.length);
		if (indx < 7) {
			indx++;
			setImage(indx);
		} else
		setImage(1);
	    setTimeout("updateImage()",7000);
	}
}