user_sidenav.php

<div class="col-sm-2 sidenav">
  <div class="panel panel-default">
    <div class="panel-heading">Hello <br/><?php echo $username ;?>
    </div>
    <div class="panel-body">
    <!-- <ul class="list-group text-left">
    <li class="list-group-item"><a href="#" class="list-group-item">Your Transactions</a></li>
    <li class="list-group-item"><a href="#">Your Orders</a></li>
    <li class="list-group-item"><a href="#">Books Recommended</a></li>
    </ul>-->
  <div class="list-group">
    <a href="User_profile.php" class="list-group-item">Your profile</a>
    <!--<a href="#" class="list-group-item">Your Transactions</a>-->
    <a href="YourBooks_sell.php" class="list-group-item">Your Books Up for Sale!</a>
    <a href="YourOrders.php" class="list-group-item">Your Orders</a>
    <a href="User_buysoldbooks.php?op=1" class="list-group-item">Books Sold</a>
    <a href="User_buysoldbooks.php?op=2" class="list-group-item">Books Bought</a>
    
  <a href="Recommendedbooks.php" class="list-group-item">Books Recommended</a>
  </div>

   
    </div>
    </div>
</div>