jQuery級聯下拉問題

Question

我已經在這裏得到了一些幫助，但不幸的是，我仍然在級聯下拉上苦苦掙扎。我需要下面的<select>根據#city，上面的一個<select>框的選擇進行更新。

我的代碼中是否有任何明顯的錯誤？

HTML/jQuery的：

<select name="club" class="dropdown" id="club"> 
<script> 

$('#city').change(function(){ 
    var $club = $('#club'); 
    $club.find('option:not([value="default"])').remove(); //Remove previous items 
    $.getJSON('getClubs.php', {city:$(this).val()}, function(clubs){ 
     $.each(clubs, function(index, city){ 
      $club.append('<option value="'+row[0]+'">'+row[1]+'</option>'); 
     }); 
    }); 
}); 

</script> 
</select> 

PHP（getClubs.php）：

<?php 

date_default_timezone_set('Europe/London'); 

$day = date("l"); 
$time = date("G"); 

if ($time >= 21) { 
    $day = date('l', strtotime($day .' +1 day')); 
    } 

$city = $_POST['city']; 

if ($day == Monday) { 
    $query = "SELECT name FROM nights WHERE city = '$city' ORDER BY FIELD(day, 'MONDAY', 'TUESDAY', 'WEDNESDAY', 'THURSDAY', 'FRIDAY', 'SATURDAY', 'SUNDAY')"; 
    } 

else if ($day == Tuesday) { 
    $query = "SELECT name FROM nights WHERE city = '$city' ORDER BY FIELD(day, 'TUESDAY', 'WEDNESDAY', 'THURSDAY', 'FRIDAY', 'SATURDAY', 'SUNDAY', 'MONDAY')"; 
    } 

else if ($day == Wednesday) { 
    $query = "SELECT name FROM nights WHERE city = '$city' ORDER BY FIELD(day, 'WEDNESDAY', 'THURSDAY', 'FRIDAY', 'SATURDAY', 'SUNDAY', 'MONDAY', 'TUESDAY')"; 
    } 

else if ($day == Thursday) { 
    $query = "SELECT name FROM nights WHERE city = '$city' ORDER BY FIELD(day, 'THURSDAY', 'FRIDAY', 'SATURDAY', 'SUNDAY', 'MONDAY', 'TUESDAY', 'WEDNESDAY')"; 
    } 

else if ($day == Friday) { 
    $query = "SELECT name FROM nights WHERE city = '$city' ORDER BY FIELD(day, 'FRIDAY', 'SATURDAY', 'SUNDAY', 'MONDAY', 'TUESDAY', 'WEDNESDAY', 'THURSDAY')"; 
    } 

else if ($day == Saturday) { 
    $query = "SELECT name FROM nights WHERE city = '$city' ORDER BY FIELD(day, 'SATURDAY', 'SUNDAY', 'MONDAY', 'TUESDAY', 'WEDNESDAY', 'THURSDAY', 'FRIDAY')"; 
    } 

else if ($day == Sunday) { 
    $query = "SELECT name FROM nights WHERE city = '$city' ORDER BY FIELD(day, 'SUNDAY', 'MONDAY', 'TUESDAY', 'WEDNESDAY', 'THURSDAY', 'FRIDAY', 'SATURDAY')"; 
    } 

    $result = mysql_query($query); 
    $items = array(); 

    if($result && mysql_num_rows($result) > 0) { 
     while ($row = mysql_fetch_array($result)) { 
      $items[] = array($row[0], $row[1]); 
      }   
    } 

    mysql_close(); 
    // convert into JSON format and print 
    echo json_encode($items); 
?>