function openCalendarPopup()
{
    var calendar = new CalendarPopup("calendarDiv");
    calendar.setReturnFunction("setCalendarDate");

    if (document.getElementById('disableDatesUntil'))
    {
      calendar.addDisabledDates(null, document.getElementById('disableDatesUntil').value);
    }

    if (document.getElementById('disableDatesAfter'))
    {
      calendar.addDisabledDates(document.getElementById('disableDatesAfter').value, null);
    }

    calendar.select(document.getElementById('calendarValue'),'calendarAnchor','MM/dd/yyyy');
}

function setCalendarDate(y, m, d)
{
  document.getElementById('year').value = y;
  document.getElementById('month').value = LZ(m);
  document.getElementById('day').value = LZ(d);
  var timestamp = new Date(y, (LZ(m) - 1), LZ(d)).getTime() / 1000;
  location.href = calendarPopupSubmitAim + timestamp;
}