function montre_menu (type, id){
	document.getElementById(type+"_left_"+id).style.visibility="visible";
	document.getElementById(type+"_right_"+id).style.visibility="visible";
}

function cache_menu (type, id){
	document.getElementById(type+"_left_"+id).style.visibility="hidden";
	document.getElementById(type+"_right_"+id).style.visibility="hidden";
}