通过ajax传递最接近的值

I have a table created using a while loop thats displays a list of items so that the user can select an item to delete which is done via ajax.

I would like to use JQuery's closest attribute but I can't work out the correct syntax. The output I get from this is Object Object

The table

<form id="del_opinion">
  <table id="asked_list">
<?php
    while($row = mysqli_fetch_assoc($result)){ 
    <tr>
       <td>
         <?php echo $row['name']; ?>
       </td>
     <td>
        <input type="button" name="del_question" value="" class="trash_btn">
            <input type="hidden" class="id_question" name="question_id" value="<? echo $row['questionID']; ?>">
            <input type="hidden" class="id_user" name="user" value="<?php echo $id; ?>"  >      
     </td>
    </tr>
<? } ?>
  </table>
</form>

The ajax

<script>
$(document).ready(function() {
$('.trash_btn').click(function(){
    var question = $(this).closest('.id_question');
    var user = $(this).closest('id_user');  
$.ajax({
        url: 'opinion_del.php',
        type:'POST',
        data: 'question='+ question +'&user='+user,
        dataType: 'json',
        success: function(response){
                $('#responses_table').html(response);
            },
            error:function (xhr, ajaxOptions, thrownError){
        alert(thrownError);
    } // End of success function of ajax form
        }); // End of ajax call    

    });
});
</script>

The php have done for testing

$question_id = $_POST['question'];
$id = $_POST['user'];
$sql = "SELECT * FROM adviceQuestion WHERE questionID = '$question_id'";
$result = mysqli_query($mysqli,$sql) or die(mysqli_error($mysqli));
if($result){
    $output = $question_id;
}
echo json_encode($output);

If I type a literal value to $output it works fine and if I type a literal value in either of the jquery vars they work correctly too so I'm convinced it is something to do with the closest syntax

I have also tried adding a class to the table row called details and using

var question = $(event.target).closest('.details').find('.id_question');

If I alert question it says [object Object]

var user = $(this).closest('id_user'); 

Change to this

var user = $(this).closest('.id_user'); 

You didnt specified a c lass "." dot ))) Maybe will help

OK, sussed it...

Changed this

var question = $(this).closest('.id_question');
var user = $(this).closest('id_user');

to

var question = $(this).next('.id_question').val();
var user = $(this).next('.id_user').val();