function hotel_onchange()
{
  var old_room_type = _room_type.value;
  var room_types_ar = new Array();

  for (var i in rooms_ar)
  {
    if (_hotel_id.value.toString() == '0' || rooms_ar[i].hotel_id == _hotel_id.value)
    {
      room_types_ar.push(rooms_ar[i].type);
    }
  }

  room_types_ar = array_unique(room_types_ar);
  room_types_ar.sort();
  _room_type.options.length = 1;

  for (var i = 0; i < room_types_ar.length; i++)
  {
    _room_type.options[_room_type.options.length] = new Option(room_types_ar[i], room_types_ar[i], room_types_ar[i]==old_room_type?true:false);
  }

  room_type_onchange();
}

function room_type_onchange()
{
  var old_room_id = _room_id.value;
  var cur_rooms_ar = new Array();

  for (var i in rooms_ar)
  {
    if (
        (
         (
          _hotel_id.value.toString() != '0' &&
          rooms_ar[i].hotel_id == _hotel_id.value
         ) ||
         _hotel_id.value.toString() == '0'
        ) &&
        (
         (
          _room_type.value != '' &&
          rooms_ar[i].type == _room_type.value
         ) ||
         _room_type.value == ''
        )
       )
    {
      cur_rooms_ar.push({id:i,title:rooms_ar[i].title});
    }
  }

  cur_rooms_ar.sort();
  _room_id.options.length = 1;

  for (var i = 0; i < cur_rooms_ar.length; i++)
  {
    var o = new Option(cur_rooms_ar[i].title, cur_rooms_ar[i].id, cur_rooms_ar[i].id==old_room_id?true:false);
    _room_id.options[_room_id.options.length] = o;
  }
}