function one_night() {

sstemp = new Date(arrivalyear,arrivalmonth-1,arrivalday);
ss = sstemp.getTime();

dayuvweak = new Date (ss);
dayuvweak = dayuvweak.getDay()

if (lang == "english")
{oneday_textt = "It is not possible to book only one night on a Friday or Saturday.";}

if (lang == "spanish")
{oneday_textt = "No se puede reservar una noche los viernes o sábados.";}

if ((dayuvweak > 4) && (dz == 1))
{
window.alert(oneday_textt)
nodis = false;
return false;
}
}