I'm getting a PHP error and I can't get why I got it
<p>I'm making my first website with some PHP involved and I'm getting an error every time I press an action button on a previous page. This is a text of an error:</p>

<blockquote>
  <p>Warning: require_once(./include/config.php) [function.require-once]: failed to open stream: No such file or directory in /var/www/u5161155/data/www/sh0rt.ru/submit.php on line 2</p>
  
  <p>Fatal error: require_once() [function.require]: Failed opening required './include/config.php' (include_path='.:') in /var/www/u5161155/data/www/sh0rt.ru/submit.php on line 2</p>
</blockquote>

<p>This is my code</p>

<pre><code>&lt;?php
require_once "./include/config.php";
require_once "./include/ShortUrl.php";

if ($_SERVER["REQUEST_METHOD"] != "POST" || empty($_POST["url"])) {
    header("Location: shorten.html");
    exit;
} 

try {
    $pdo = new PDO(DB_PDODRIVER . ":host=" . DB_HOST . ";dbname=" . DB_DATABASE,
        DB_USERNAME, DB_PASSWORD);
}
catch (\PDOException $e) {
    header("Location: error.html");
    exit;
}

$shortUrl = new ShortUrl($pdo);
try {
    $code = $shortUrl-&gt;urlToShortCode($_POST["url"]);
}
catch (\Exception $e) {
    header("Location: error.html");
    exit;
}
$url = SHORTURL_PREFIX . $code;

echo &lt;&lt;&lt;ENDHTML
&lt;html&gt;
 &lt;head&gt;
  &lt;title&gt;URL Shortener&lt;/title&gt;
 &lt;/head&gt;
 &lt;body&gt;
  &lt;p&gt;&lt;strong&gt;Short URL:&lt;/strong&gt; &lt;a href="$url"&gt;$url&lt;/a&gt;&lt;/p&gt;
 &lt;/body&gt;
&lt;/html&gt;
ENDHTML;
</code></pre>

<p>I understand an error, but I can't get why it doesn't open it. I got the right file in the right directory. That's why I'm asking for help</p>
