Форма не публикует данные

у меня есть следующий HTML-код:

<form class="dropzone" id="msform" enctype="multipart/form-data">                                   <!-- multistep form --><!-- progressbar -->
<ul id="progressbar">
<li class="active">Account Setup</li>
<li>Post an Image</li>
</ul>
<!-- fieldsets -->
<fieldset>
<h2 class="fs-title">Fill in Some General Details</h2>
<h3 class="fs-subtitle">As Simple As This</h3>
<input type="text" name="update" id="title" placeholder="Update Title" />
<textarea name="description" id="description" placeholder="Short Description/Add On"></textarea>
<input type="date" name="expire" id="expire" placeholder="Expire By" value="Expire By" />
<input type="button" name="next" class="next action-button" value="Next" />

</fieldset>
<fieldset>
<h2 class="fs-title">Upload Image</h2>
<h3 class="fs-subtitle">We currently only support images.</h3>
<div class="dropzone-previews dz-message" id="dropzonePreview">

</div>

<input type="button" name="previous" class="previous action-button" value="Previous" />
<input type="submit"  name="submit" class="submit action-button" value="Submit"/>
</fieldset>

</form>
</div>
</div>

<script>
Dropzone.options.msform = { // The camelized version of the ID of the form element

// The configuration we've talked about above
url: "filepostupload.php",
autoProcessQueue: false,
autoDiscover: false,
addRemoveLinks: true,
uploadMultiple: false,
parallelUploads: 5,
maxFiles: 5,
paramName: "file",
previewsContainer: '.dropzone-previews',
clickable:'#dropzonePreview', //used for specifying the previews div
//used this but now i cannot click on previews div to showup the file select dialog box// The setting up of the dropzone
init: function() {
var myDropzone = this;
this.element.querySelector("input[type=submit]").addEventListener("click", function(e) {
// Make sure that the form isn't actually being sent.
e.preventDefault();
e.stopPropagation();
if (myDropzone.getQueuedFiles().length === 0) {
var update =  $('#title').val();
var description =  $('#description').val();
var expiry =  $('#expire').val();
var groupid =  <?php echo $groupid ?>;
var request = $.ajax({
url: "updatesnofile.php",
type: "POST",
data: { update:update, description:description, expiry:expiry, groupid:groupid},
dataType:"text",

success: function(data) {
if (data=="success") {
alert('success');} else  {

alert(data);

}
},
error: function(request, err){alert(err);}
});
}else {
myDropzone.processQueue();

}
});// Listen to the sendingmultiple event. In this case, it's the sendingmultiple event instead
// of the sending event because uploadMultiple is set to true.
this.on("sending", function() {
// Gets triggered when the form is actually being sent.
// Hide the success button or the complete form.
});
this.on("success", function(files, response) {
// Gets triggered when the files have successfully been sent.
// Redirect user or notify of success.
alert(response);
});
this.on("error", function(files, response) {
alert("error");
});
}

}
</script>

И мой PHP-скрипт, который выполняет загрузку файлов:

<?php
session_start();
require 'config.php';
//I'm using mysql_ as an example, it should be PDO

$ds = DIRECTORY_SEPARATOR;
$foldername = "updatefiles/";
if (isset($_POST['update']) && isset($_POST['description']) && isset($_POST['expiry']) && isset($_POST['groupid'])){
$title= mysqli_real_escape_string($mysqli,trim($_POST['update']));
$description= mysqli_real_escape_string($mysqli,trim($_POST['description']));
$expire= mysqli_real_escape_string($mysqli,trim($_POST['expiry']));
$groupid= mysqli_real_escape_string($mysqli,trim($_POST['groupid']));

$fileupload = basename($_FILES['file']['name']);
$fileType = $_FILES['file']['type'];
$fileSize = $_FILES['file']['size'];

$tempFile = $_FILES['file']['tmp_name'];
$targetPath = dirname( __FILE__ ) . $ds. $foldername . $ds;
$targetFile =  $targetPath. $fileupload;
move_uploaded_file($tempFile,$targetFile);

$fileupload = mysqli_real_escape_string($mysqli,basename($_FILES['file']['name']));
$fileType = mysqli_real_escape_string($mysqli,$_FILES['file']['type']);
$fileSize = mysqli_real_escape_string($mysqli,$_FILES['file']['size']);
mysqli_query($mysqli,"START TRANSACTION;");
$ins = mysqli_query($mysqli,"INSERT INTO posts (category, description, posttitle, userid, expire, group_id) VALUES ('updates','".$description."', '".$title."','{$_SESSION['userid']}', '".$expire."','".$groupid."' )");
if (!$ins) {
// fail
mysqli_query($mysqli,"ROLLBACK");
echo"error with first insert";
return FALSE;

}

$upd = mysqli_query($mysqli,"SET @post_id_in_posts = LAST_INSERT_ID()");
if (!$upd) {
// fail
mysqli_query($mysqli,"ROLLBACK");
echo"error with setting postid";
return FALSE;
}

$del = mysqli_query($mysqli, "INSERT INTO files (post_id,f_name, f_type, f_size) VALUES (@post_id_in_posts,'".$fileupload."', '".$fileType."', '".$fileSize."')");
if (!$del) {
// fail
mysqli_query($mysqli,"ROLLBACK");
echo "Error with Second Insert!";
return FALSE;
}

// All succeeded
mysqli_query($mysqli,"COMMIT");
echo"success";
return TRUE;

}else {
echo"formwasnotsubmitted";}

?>

Тем не менее, он постоянно говорит мне, что форма не была отправлена ​​(что означает, что отправка формы по зонам сбоя не удалась, и, следовательно, данные не публикуются при наличии файлов, ajax работает, хотя при отсутствии файлов), кто-нибудь может узнать почему? Спасибо!

Мне удалось найти ошибку, это связано с тем, как Dropzone отправляет данные формы!