function calc_check_out_date() {
  var form = document.forms['search'];
  var check_in_date = form.elements['check_in_date'].value;
  var nights_cnt = parseInt(form.elements['nights_cnt'].value);

  if (!nights_cnt) {
    nights_cnt = 1;
    form.elements['nights_cnt'].value = 1;
  }

  if (check_in_date.length >= 6) {
    var check_in_date_array = check_in_date.split(".");
    if (check_in_date_array.length < 3) return;
    sday = check_in_date_array[0];
    if (sday.length == 1)
      sday = "0" + sday;
    smonth = check_in_date_array[1];
    if (smonth.length == 1)
      smonth = "0" + smonth;
    syear = check_in_date_array[2];

    var tmp_date = new Date(syear, smonth-1, sday);
    tmp_date.setDate(tmp_date.getDate()+nights_cnt);

    dd = tmp_date.getDate();
    mm = tmp_date.getMonth()+1;
    yyyy = tmp_date.getYear();
    if (yyyy < 1000) yyyy += 1900; // Y2K fix   
    mymanth = "" + mm;
    myday = "" + dd;
    if (myday.length == 1)
      myday = "0" + myday;
    if (mymanth.length == 1) {
      mymanth = "0" + mymanth;
    }
    form.elements['check_out_date'].value = myday + '.' + mymanth + '.' + yyyy;
  }
}

function calc_nights() {
  var form = document.forms['search'];
  var check_in_date = form.elements['check_in_date'].value;
  var check_out_date = form.elements['check_out_date'].value;

  if (check_in_date.length >= 6 && check_out_date.length >= 6 ) {
    var check_in_date_array = check_in_date.split(".");
    if (check_in_date_array.length < 3) return;
    sday = check_in_date_array[0];
    if (sday.length == 1)
      sday = "0" + sday;
    smonth = check_in_date_array[1];
    if (smonth.length == 1)
      smonth = "0" + smonth;
    syear = check_in_date_array[2];

    var start_date = new Date(syear, smonth-1, sday);

    var check_out_date_array = check_out_date.split(".");
    if (check_out_date_array.length < 3) return;
    sday = check_out_date_array[0];
    if (sday.length == 1)
      sday = "0" + sday;
    smonth = check_out_date_array[1];
    if (smonth.length == 1)
      smonth = "0" + smonth;
    syear = check_out_date_array[2];

    var end_date = new Date(syear, smonth-1, sday);

    if (start_date < end_date) form.elements['nights_cnt'].value = Math.round((end_date.getTime()-start_date.getTime())/(24 * 60 * 60 * 1000));
    else {
      end_date.setDate(end_date.getDate()+1);
      form.elements['nights_cnt'].value = 1;
    }
  }
}