存储JQuery中的选项值

我是JQuery的初学者，我想问你一些问题。如何将目的地选项值从jquery存储到PHP？这是我的代码：

destination = {
"xpress": ["Pekanbaru", "Medan", "Jayapura"],
"fast": ["Jakarta", "Yogyakarta", "Pontianak"]}
$(document).ready(function() {
if($(this).data('options') == undefined){
$("#destination").html('');
 $.each(destination['xpress'], function(i, city) {
        $("<option>").attr("value", city).text(city).appendTo("#destination");
    });
}
$('#airlines').change(function() {
   var airlines = $(this).val();
if(destination[airlines] && destination[airlines].length > 0)
$("#destination").html('');
 $.each(destination[airlines], function(i, city) {
        $("<option>").attr("value", city).text(city).appendTo("#destination");
    });
});
});
</script>
</head>
<?php
if(isset($_POST['submit'])){
    $airlines = $_POST['airlines'];
    $destination = $_POST['destination'];
    $qty = $_POST['qty'];
    echo "<br><br>".$airlines."  ".$destination."  ".$qty;
}
?>

echo$destination不显示任何内容。

这是html代码：

       <form method="post" action=<?php $_SERVER['PHP_SELF']?>>
       <table border="1" align="center" width="300px" height="15px">
       <tr>
       <td align="center" colspan="3">Ticket</td>
       </tr>
       <tr align="center">
       <td>Airlines</td>
       <td>Destination</td>
       <td>Qty</td>
       </tr>
       <tr>
       <td><select name="airlines" id="airlines">
       <option value="xpress">Xpress Air</option>
       <option value="fast">Fast Air</option>
       </select>
       </td>
       <td>
       <select nama="destination" id="destination">
       </select>
       </td>
       <td>
       <select name="qty" id="qty">
        <option value="1">1</option>
        <option value="2">2</option>
        <option value="3">3</option>
        <option value="4">4</option>
        </select>
       </td>
       </tr>
       <tr>
<td><input type="submit" name="submit" value="Submit" id="submit"/>
</td>
</tr>
</table>
</form>

我不知道如何获取值并存储到php的变量中。