function vis( par ) {
	objs = document.getElementsByClassName( "menus" );
	var n_objs = objs.length;
	for ( var i = 0; i < n_objs; i++ ) {
		objs[ i ].style.display = "none";
	}
	objs = document.getElementsByClassName( "menu_" + par );
	var n_objs = objs.length;
	for ( var i = 0; i < n_objs; i++ ) {
		objs[ i ].style.display = "block";
	}
}