สอบถามปัญหาการใช้ ajax จากฟอร์มไม่ส่งค่าไป insert ครับ

                <form method="post" enctype="multipart/form-data">
                <div class="form-group">
                      <label>File upload :</label>
                      <input type="file" class="file-upload-default file-upload-info" name="multiple_files" id="multiple_files" multiple>
                      <div class="input-group col-xs-12">
                        <input  class="form-control file-upload-info" disabled="" placeholder="อัพโหลดไฟล์">
                        <span class="input-group-append">

         <!-- 2 input นี้ ค่าไม่ถูกส่งไปยัง ajax -->

                        <input type="hidden" class="form-control file-upload-info" id="idr_assign_uppf" name="idr_assign_uppf" value="<?php echo base64_encode($selAssigSend['id_assig']);?>">
                        <input type="hidden" id="iduserss_uppf" name="iduserss_uppf" value="<?php echo base64_encode($_SESSION['id_us']);?>">

                          <button class="file-upload-browse btn btn-primary" type="button">อัพโหลดไฟล์</button>
                        </span>
                      </div>
                    </form>
                      <label>ประเภทไฟล์ที่รองรับ .jpg, png, .gif file allowed</label>
                      <HR> 
                <h3 align="center"><b> ไฟล์ของคุณที่อัพโหลด </b></h3>
                      <span id="error_multiple_files"></span>
                      <br />
                      <div class="table-responsive" id="image_table"></div>
                </div>

<script>
$(document).ready(function(){
 load_image_data();
 function load_image_data()
 {
  $.ajax({
   url:"pages/assignments/lib/testt/fetch.php",
   method:"POST",
   success:function(data)
   {
    $('#image_table').html(data);
   }
  });
 } 
 $('#multiple_files').change(function(){
  var error_images = '';
  var form_data = new FormData();
  var files = $('#multiple_files')[0].files;

  if(files.length > 10)
  {
   error_images += 'You can not select more than 10 files';
  }
  else
  {
   for(var i=0; i<files.length; i++)
   {
    var name = document.getElementById("multiple_files").files[i].name;
    var ext = name.split('.').pop().toLowerCase();
    if(jQuery.inArray(ext, ['gif','png','jpg','jpeg','pdf']) == -1) 
    {
     error_images += '<p>Invalid '+i+' File</p>';
    }
    var oFReader = new FileReader();
    oFReader.readAsDataURL(document.getElementById("multiple_files").files[i]);
    var f = document.getElementById("multiple_files").files[i];
    var fsize = f.size||f.fileSize;
    if(fsize > 2000000)
    {
     error_images += '<p>' + i + ' File Size is very big</p>';
    }
    else
    {
     form_data.append("file[]", document.getElementById('multiple_files').files[i]);

    }
   }
  }
  if(error_images == '')
  {
    
   $.ajax({
    url:"pages/assignments/lib/testt/upload.php",
    method:"POST",
    data: form_data,
    contentType: false,
    cache: false,
    processData: false,
    beforeSend:function(){
     $('#error_multiple_files').html('<br /><label class="text-primary">Uploading...</label>');
    },   
    success:function(data)
    {
     $('#error_multiple_files').html('<br /><label class="text-success">Uploaded</label>');
     load_image_data();
    }
   });
  }
  else
  {
   $('#multiple_files').val('');
   $('#error_multiple_files').html("<span class='text-danger'>"+error_images+"</span>");
   return false;
  }
 });  
 $(document).on('click', '.edit', function(){
  var image_id = $(this).attr("id");
  $.ajax({
   url:"pages/assignments/lib/testt/edit.php",
   method:"post",
   data:{image_id:image_id},
   dataType:"json",
   success:function(data)
   {
    $('#imageModal').modal('show');
    $('#image_id').val(image_id);
    $('#image_name').val(data.image_name);
    $('#image_description').val(data.image_description);
   }
  });
 }); 
 $(document).on('click', '.delete', function(){
  var image_id = $(this).attr("id");
  var image_name = $(this).data("image_name");
  if(confirm("คุณแน่ใจใช่ไหม?? ที่จะลบไฟล์นี้ออก หากแน่ใจกดปุ่ม ตกลง หรือไม่ต้องการลบกด ยกเลิก?"))
  {
   $.ajax({
    url:"pages/assignments/lib/testt/delete.php",
    method:"POST",
    data:{image_id:image_id, image_name:image_name},
    success:function(data)
    {
     load_image_data();
     alert("ระบบได้ลบรูปภาพเรียบร้อยแล้ว กรุณากดปุ่ม ตกลง");
    }
   });
  }
 }); 
 $('#edit_image_form').on('submit', function(event){
  event.preventDefault();
  if($('#image_name').val() == '')
  {
   alert("Enter Image Name");
  }
  else
  {
   $.ajax({
    url:"pages/assignments/lib/testt/update.php",
    method:"POST",
    data:$('#edit_image_form').serialize(),
    success:function(data)
    {
     $('#imageModal').modal('hide');
     load_image_data();
     alert('Image Details updated');
    }
   });
  }
 }); 
});
</script>

<?php

//upload.php
include('../b_conn.php');

if(count($_FILES["file"]["name"]) > 0)
{
 //$output = '';
 sleep(3);
 for($count=0; $count<count($_FILES["file"]["name"]); $count++)
 {
  $file_name = $_FILES["file"]["name"][$count];
  $tmp_name = $_FILES["file"]['tmp_name'][$count];
  $file_array = explode(".", $file_name);
  $file_extension = end($file_array);
  $iduserss_uppfile =  base64_decode($_POST['iduserss_uppf']);
  $idr_assign_uppfile = base64_decode($_POST['idr_assign_uppf']);

  if(file_already_uploaded($file_name, $bx_conn))
  {
   $file_name = $file_array[0] . '-'. rand() . '.' . $file_extension;
  }
  $location = 'files/' . $file_name;
  if(move_uploaded_file($tmp_name, $location))
  {
   $query = "
   INSERT INTO b_fileupp (iduserss_uppf, idr_assign_uppf, image_name, image_description) 
   VALUES ('".$iduserss_uppf."', '".$idr_assign_uppf."', '".$file_name."', '')
   ";
   $statement = $bx_conn->prepare($query);
   $statement->execute();
  }
 }
}

function file_already_uploaded($file_name, $bx_conn)
{
 
 $query = "SELECT * FROM b_fileupp WHERE image_name = '".$file_name."'";
 $statement = $bx_conn->prepare($query);
 $statement->execute();
 $number_of_rows = $statement->rowCount();
 if($number_of_rows > 0)
 {
  return true;
 }
 else
 {
  return false;
 }
}

?>