function startmenu(aperta)
{
	document.getElementById('chi_siamo').style.display = "none";
	document.getElementById('catalogo_viaggi').style.display = "none";
	document.getElementById('cosa_offriamo').style.display = "none";
	document.getElementById('download').style.display = "none";

    if (aperta != "0")
        menufunc(aperta);
}

function menufunc(menuId)
{
	if(document.getElementById(menuId).style.display == "none")
	{
		startmenu('0');
		document.getElementById(menuId).style.display = "block";
	}
	else
	{
		startmenu('0');
	}
}