Can't attach files from form using phpMailer - php

Question

I need send an email with attachments (words, pdf...) from a Contact form.
The email is sent well, but with .pdf not attached and with .docx I have a file without extension (choosing office to run it looks perfectly)
This is my code:
<form method="post" action="components/trabajamail.php" enctype="multipart/form-data">
<input type="file" name="userfile" accept="application/pdf,application/msword">
<button type="submit">Send</button>
My php file based on This:
$mail = new PHPMAILER ();
$mail->setFrom ( 'from#mail.com', 'Mailer' ); // Add a recipient
$mail->addAddress ( 'to#mail.com' );
$mail->isHTML ( true ); // Set email format to HTML
$mail->Subject = 'Subject';
$mail->Body = "Message";
$mail->CharSet = 'UTF-8';
// Attach the uploaded file
if (array_key_exists ( 'userfile', $_FILES )) {
$uploadfile = tempnam ( sys_get_temp_dir (), sha1 ( $_FILES ['userfile'] ['name'] ) );
if (move_uploaded_file ( $_FILES ['userfile'] ['tmp_name'], $uploadfile )) {
$mail->addAttachment ( $uploadfile, 'File' );
}
}
if (! $mail->send ()) {
echo "<div class='alert alert-warning'><strong>Error!</strong></div>";
} else {
echo "<div class='alert alert-success'><strong>Success!</strong></div>";
}
The last if never show me nothing, but i cant find the problem
I have read some threads with similar problems and I have used examples from the officinal page but I do not get this to work