array_push($pnagArticles, array('itemId' => $article['articleId'], 'productNumber' => $article['articleNumber'], 'title' => $article['articleTitle'], 'description' => $article['articleDescription'], 'quantity' => $article['articleQuantity'], 'unitPrice' => number_format($article['articlePrice'], 2, '.', ''), 'tax' => number_format($article['articleTax'], 2, '.', '')));
}
$invoiceNumber = "10234";
$customerNumber = "10234";
$orderNumber = "10234";
try {
    $comment = 'must not be left empty for confirmed invoices, editing an invoice will result in refunded items';
    $PnagInvoice->updateInvoice($transactionId, $pnagArticles, $comment, $invoiceNumber, $customerNumber, $orderNumber);
} catch (XmlToArrayException $e) {
}
/**
 * Get a web file (HTML, XHTML, XML, image, etc.) from a URL.  Return an
 * array containing the HTTP server response header fields and content.
 */
function getWebPage($url)
{
    $options = array(CURLOPT_RETURNTRANSFER => true, CURLOPT_HEADER => false, CURLOPT_FOLLOWLOCATION => true, CURLOPT_ENCODING => "", CURLOPT_USERAGENT => "sofort example", CURLOPT_AUTOREFERER => true, CURLOPT_CONNECTTIMEOUT => 120, CURLOPT_TIMEOUT => 120, CURLOPT_MAXREDIRS => 10, CURLOPT_SSL_VERIFYPEER => false);
    $ch = curl_init($url);
    curl_setopt_array($ch, $options);
    $content = curl_exec($ch);
    $err = curl_errno($ch);
    $errmsg = curl_error($ch);
    $header = curl_getinfo($ch);
    curl_close($ch);
    $header['errno'] = $err;
    $header['errmsg'] = $errmsg;
    $header['content'] = $content;
    return $header;
}
echo $PnagInvoice->getTransactionId();