Updating selected lang

<div class="selected-lang">
    <!--Keep the selected language name updated; this is how translations for the website are implemented-->
    <?php echo $lang['lang_name'] ?>
    <!--Keep the flag for the currently selected language updated-->
    <style>
        .selected-lang:before { background-image: url(./images/<?php echo $_SESSION['lang']?>.png); }
    </style>
</div>