function one_night() {

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

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



//IF USING THE FRENCH WE HAVE NO LANG
if (lang == undefined)
{
lang="eng"
} 

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

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




if (dz == 1)
{
if ((dayuvweak == 0) || (dayuvweak > 4))
{
window.alert(oneday_textt)
holsupdays = false;
return false;
}

}




}