jQuery：将新值放入犹太教堂隐藏输入

我试图通过ajaxjquery将ID数据库输入到输入中，以将数据发送到另一个表。由于某种原因，我无法获取值​​输入的类型，仅适用于DIV。我的代码有什么问题

<?php echo form_open_multipart('articles/add_new_article'); ?>


  <p>
 <?php echo form_label('ערוץ כתבה:'); ?>
 <select name="category">
  <?php
          foreach ($all_sections->result() as $section) : ?>

   <option value="<?php echo $section->name;?>"><?php echo $section->name;?></option>



   <?php endforeach; ?>
 </select>

 </p>

  <p>
    <?php
    $data = array(
      'name'        => 'title',
      'value'       => set_value('title')
    );
?>

    <?php echo form_input($data); ?>

      </p>


   <p>
   <?php echo form_label('פתיח'); ?>

      <?php
       $data = array(
      'name'        => 'abstract',
      'value'       => set_value('abstract')
    );
    ?>

       <textarea id="abstract" name="abstract" cols="80" rows="10" ></textarea>

       </p>

  <p>

  הוסף תמונה ראשית לכתבה:

 <?php echo form_upload("userfile");?>


</p>

   <?php if (!empty($error)) {print_r($error);}?>

       <?php echo form_label('שם כותב:'); ?>

   <?php
    $data = array(
      'name'        => 'name',
      'value'       => set_value('name')
    );
      ?>

     <?php echo form_input($data); ?>

 </p>



    <?php echo form_label('תוכן:'); ?>
     <div id="text_body">
    <p>
  <?php
   $data = array(
      'name'        => 'body',
      'value'       => set_value('body')

    );
   ?>

      <textarea id="body" name="body" class="editme" rows="20" cols="150" ></textarea>

    </p>


    <p>
   <?php echo form_label('סטטוס כתבה:'); ?>


     <?php $options = array(
          'מוצג'  => 'מוצגת',
          'מוסתר' => 'מוסתרת',
          'סגור'   => 'סגורה'
        );
     echo form_dropdown('status', $options); ?>

  </p>

     <!--Submit Buttons-->
         <?php $data = array(
            "value" => "הוסף כתבה",
            "name" => "submit",
            "id" => "main-submit",
            "class" => "btn btn-primary"); ?>



    <p>
   <?php echo form_submit($data); ?>
   </p>

    <?=form_hidden('user_editor', $this->session->userdata('username'));?> 

   <?php  $data = array(
            "name" => "main_inner",
            "id" => "main_inner" ); ?>

    <?=form_hidden($data);?> 

   <input name="number" type="hidden" id="number" value="">


     <?php echo form_close(); ?>



         <h3>הוסף תמונות לכתבה</h3>
  <form action="" method="post" id="data" accept-charset="utf-8" enctype="multipart/form-  data">


 <input type="file" id="file" multiple name="userfile[]" size="20" />
  <br /><br />


         <input id="submit" type="submit" value="שלח!" />

    </form>

      <div id="inner">תמונות הכתבה:</div>

 <script type="text/javascript">

        $(function(){
    $('#main-submit').click(function () {
        var mysave = $('#inner').html();
        $('#body').val(mysave);
    });
});

  $("form#data").submit(function(event){

   event.preventDefault();

   var formData = new FormData($(this)[0]);

   $.ajax({
    url: "<?=base_url();?>upload/do_upload",
    type: "POST",
    data: formData,
    async: false,
    success: function (msg) {
       $('#number').val("value = " + $('#number').val().replace("placeholder", msg))

    },
    cache: false,
    contentType: false,
    processData: false
});

     });

    </script>
   </div>

控制员：

    function do_upload()
    {

$this->load->library('upload');
$this->load->model('Files_model');
$files = $_FILES;
$cpt = count($_FILES['userfile']['name']);
for($i=0; $i<$cpt; $i++)
{

    $_FILES['userfile']['name']= $files['userfile']['name'][$i];
    $_FILES['userfile']['type']= $files['userfile']['type'][$i];
    $_FILES['userfile']['tmp_name']= $files['userfile']['tmp_name'][$i];
    $_FILES['userfile']['error']= $files['userfile']['error'][$i];
    $_FILES['userfile']['size']= $files['userfile']['size'][$i];

       $id = $this->Files_model->insert_file($_FILES['userfile']['name']); 
    //echo '<img src="'. base_url(). 'images/'. $_FILES['userfile']['name']. '">';
    //echo "<br>";
    echo $id;
    echo ",";



$this->upload->initialize($this->set_upload_options());
if ($this->upload->do_upload()) {




}


}

---

代码中的数字输入在哪里？这里：