<div class="sidebar">
        <h2><i class="fas fa-home"></i></h2>

            <li class="item" id='main'>
                <a href="main.php" class="btn"><i class="fas fa-home"></i>Strona główna</a>

            </li>

            <li class="item" id='cart'>
                <a href="koszyk.php" class="btn"><i class="fas fa-shopping-cart"></i>Koszyk</a>

            </li>
            <li class="item" id='products'>
                <a href="#products" class="btn"><i class="fab fa-product-hunt"></i><span class="soc_icon">Produkty</span></a>
                <div class="smenu">
                    <a href="#">RTV</a>
                    <a href="#">EURO</a>
                    <a href="#">AGD</a>
                </div>
            </li>
            <li class="item" id='socials'>
                <a href="#socials" class="btn"><i class="fas fa-address-book"></i>Kontakt</a>
                <div class="smenu">
                     <a href="#"><i class="fas fa-envelope"></i>Mail</a>
                     <a href="#"><i class="fab fa-twitter"></i><span class="soc_icon">Twitter</span></a>
                     <a href="#"><i class="fab fa-facebook-square"></i><span class="soc_icon">Facebook</span></a>
                </div>
            </li>
            <li class="item">
                <a href="wyloguj.php" class="btn"><i class="fas fa-sign-out-alt"></i>Wyloguj</a>
            </li>
        <span class="logged_user">
            <?php
            $user=mysqli_query($connect_mysql,"select login from data where id='{$_SESSION['registry']}';") or die ("Błąd wypisywania uzytkownikow");
                    while($check_user=mysqli_fetch_array($user)){
                        $_SESSION['registry']=$check_user[0];
                    }
                        echo "<span class='logged_user'>Witaj:".$_SESSION['registry']."</span>";
            ?>
        </span>
    </div>