Jquery Formular absenden

unction submitData() {

    $('#articleForm').submit(function (event) {  
        event.preventDefault();
        $.ajax({
            type: 'POST',  
            url: 'insertData.php',  
            data: $(this).serialize(),
            success: function () {
                $('#submitArticle').removeClass("btn btn-primary").addClass("btn btn-danger");  
            }
        });
        $("#articleForm").reset();  

    });
}

private function generateView()
    {
        $this->generatePageHeader('Verwaltung');  
        $this->generateMenu();
        $articleName = $_POST['articleName'];  
        $article = new Article();
        $sL = new StorageLocation();
        $storeageName = $sL->generateDropdownStoreageName();
        echo <<< showHTML
<h1>$articleName</h1>
showHTML;
        $a = $article->showStockOptionized($articleName, "1");  
        $fullAvailable = $article->showStockOptionized($articleName, "0");  

        foreach ($a as $key => $value) {
            echo <<< showHTML
            <div class="inline">  
            <h3><span class="label label-primary">Optioniert<span class="badge">$value</span></span></h3>  
</div>
showHTML;
        }
        foreach ($fullAvailable as $key => $value) {
            echo <<< showHTML
            <div class=inline>
            <h3><span class="label label-primary">Bestand<span class="badge">$value</span></span></h3>  
            </div>
showHTML;




        
            echo <<< showHTML
            <button type="link" class="btn btn-link" data-toggle="modal" data-target="#myModal">  
            <span class="glyphicon glyphicon-info-sign"></span>  
            Info
            </button>
<!-- Modal -->
<div id="myModal" class="modal fade" role="dialog">  
  <div class="modal-dialog">  

    <!-- Modal content-->
    <div class="modal-content">  
      <div class="modal-header">  
        <button type="button" class="close" data-dismiss="modal">&times;</button>  
        <h4 class="modal-title">Modal Header</h4>  
      </div>
      <div class="modal-body">  
        <p> Einlagerungs informationen anzeigen</p>
      </div>
      <div class="modal-footer">  
        <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>  
      </div>
    </div>

  </div>
</div>

showHTML;
            }


        echo <<< showHTML

<div class="container">  
  <h2>Artikel hinzufügen</h2>
  <form class="form" id="articleForm">  
  <select name="dropStatus" size="1" id="dropStatus" onchange="readOnlyInput();">  
  <option selected value="0">Einlagern</option>  
  <option value="1">Bestätigt</option>  
  </select>
  <select name="dropStoreageName" size="1" id="dropDwn">  
<option selected> Lagerort</option>
showHTML;
        foreach ($storeageName as $key => $value) {
            $value = htmlspecialchars($value);
            $key = htmlspecialchars($key);
            echo <<< showHTML
        <option value="$key">$value</option>  
showHTML;
        }

        echo <<< showHTML
    </select>     
  
    <div class="form-group">  
      <label for="article">Artikel:</label>  
      <input type="text" name="article" class="form-control" id="article" value="$articleName" placeholder="Artikelname" readonly>                 
    </div>
    <div class="form-group">  
      <label for="comment">Kommentar:</label>  
      <input type="text" name="comment" class="form-control" id="comment" placeholder="Kommentar eingeben">  
     </div>
    <div class="form-group">  
      <label for="customer">Kunde:</label>  
      <input type="text" name="customer" class="form-control" id="customer" placeholder="Kunde eingeben" readOnly>  
     </div>
    <div class="form-group">  
      <label for="amount">Menge:</label>  
      <input type="text" name="amount" class="form-control" id="amount" placeholder="Menge eingeben">  
     </div>
      <div class="form-group">  
      <label for="amount">min Bestand</label>  
      <input type="text" name="minStock" class="form-control" id="minStock" placeholder="min. Bestand eingeben">  
     </div>
      
     <input type="submit" name="submitArticle" class="btn btn-primary" value="Speichern" id="submitArticle" onclick="submitData();"/>  
           
</form>
</div>

showHTML;



        $test = $article->getArticleHistory($articleName);

        foreach ($test as $key => $value) {
            echo <<< showHTML
        <p> $key $value </p>
showHTML;

        }


        $this->generatePageFooter();
    }

require_once './Page.php';  
require_once './Article.php';  

        if (isset($_POST['submitArticle'])) {  
            $article = $_POST['article'];  
            $comment = $_POST['comment'];  
            $amount = [$_POST['amount']];  
            $storeageLocation = $_POST['dropStoreageName'];  
            $status = $_POST['dropStatus'];  
            $minStock = $_POST['minStock'];  
            $customer = $_POST['NULL'];  
            $storeArticle = new Article();
            $storeArticle->addNewArticle($status, $customer, $article, $minStock, $comment,$storeageLocation, $amount);

        }

class Article extends Page
{
    
function __construct()
{
parent::__construct();

}
public function addNewArticle($status, $customer, $article, $minStock, $comment, $storeageLocation, $amount)
    {

        for ($i = 0; $i < $amount; $i++) {
            $sql = "INSERT INTO stock(status,customer,articleName,minStock,comment,f_storageLocationID) VALUES('$status','$customer','$article','$minStock','$comment','$storeageLocation')";  
            if ($sql) {
                throw new Exception('Fehler beim scheiben in die Datenbank' . $sql);  
            }

            mysqli_query($this->db, $sql);
        }
    }