Why does my page turn blank when i insert this line of PHP code into my navigation bar? the navigation works correctly without the PHP code in it.
This is my code:
<section id="header">
        <div class="header container">
            <div class="nav-bar">
                <div class="banner-title">
                    <a href="#home"><h1><span>K</span>LJ <span>N</span>ieuwrode</h1></a>
                </div>
                <div class="nav-list">
                    <div class="hamburger"><div class="bar"></div></div>
                    <ul>
                        <li><a href="#home" data-after="Home">Home</a></li>
                        <li><a href="#nieuws" data-after="Nieuws">Nieuws</a></li>
                        <li><a href="#maandprogrammas" data-after="Maandprogrammas">Maandprogramma's</a></li>
                        <li><a href="index2-albums.php" data-after="Foto's">Foto's</a></li>
                        <li><a href="#verhuur" data-after="Verhuur">Verhuur</a></li>
                        <li><a href="#groepsleiding" data-after="Leiding">Leiding</a></li>
                        <li><a href="#contact" data-after="Contact">Contact</a></li>
                        <?php
                            if (isset($_SESSION["useruid"])) {
                                echo "<li><a href="../admin/admin.php" data-after="Admin">Log In</a></li>";
                            }
                            else {
                                echo "<li><a href="login.php" data-after="Login">Log In</a></li>";
                            }
                        ?>
                    </ul>
                </div>
            </div>
        </div>
    </section>
 
    