function showMenu(_id_menu){
	document.getElementById("sous_menu_"+_id_menu).style.display = "block";
	if (_id_menu == 1)
		document.getElementById("img_menu_"+_id_menu).src = "interface/images/bt_actualite_on.png";
	if (_id_menu == 2)
		document.getElementById("img_menu_"+_id_menu).src = "interface/images/bt_presentation_on.png";
	if (_id_menu == 3)
		document.getElementById("img_menu_"+_id_menu).src = "interface/images/bt_resultat_on.png";
}

function hideMenu(_id_menu){
	document.getElementById("sous_menu_"+_id_menu).style.display = "none";
	if (_id_menu == 1)
		document.getElementById("img_menu_"+_id_menu).src = "interface/images/bt_actualite_out.png";
	if (_id_menu == 2)
		document.getElementById("img_menu_"+_id_menu).src = "interface/images/bt_presentation_out.png";
	if (_id_menu == 3)
		document.getElementById("img_menu_"+_id_menu).src = "interface/images/bt_resultat_out.png";
}