/**
 * When the arrival date is changed, then change the default value of
 * the departure date to match (as long as the departure date hasn't
 * already been set).
 */
function set_departure_default() {
    var form = document.istay_form;

    if (typeof(form) == 'undefined') {
        return false;
    }

    if (form['DateOut'].value) {
        return;
    }

    form['DateOut'].value = reformat_date(form['DateIn'].value, 1);
}

function reformat_dates(form) {
    form['DateIn'].value = reformat_date(form['DateIn'].value, 0);
    form['DateOut'].value = reformat_date(form['DateOut'].value, 0);
}

function reformat_date(date, offset) {
    var date_str = date.replace(/\-/g, '/');
    var default_date = new Date(date_str);
    if (default_date.toString() == 'Invalid Date') {
        return;
    }

    default_date.setDate(default_date.getDate() + offset);
    var year = default_date.getFullYear();
    var month = number_pad(default_date.getMonth() + 1, 2);
    var day = number_pad(default_date.getDate(), 2);
    return month + '/' + day + '/' + year;
}

function submitIstayForm() {
    reformat_dates(document.istay_form);
    var qs;
    qs = 'hotelid=' + document.istay_form['HotelID'].value;
    qs += '&DateIn=' + document.istay_form['DateIn'].value;
    qs += '&DateOut=' + document.istay_form['DateOut'].value;
    qs += '&Rooms=' + document.istay_form['Rooms'].value;
    qs += '&Adults=' + document.istay_form['Adults'].value;
    qs += '&Children=' + document.istay_form['Children'].value;
    window.open(pageTracker._getLinkerUrl('https://booking.ihotelier.com/istay/istay.jsp?' + qs,
                                          this.target));
    return false;
}