using if isset on header to show options when user is logged in not working

I am working on a header website in CodeIgniter and I want to show the different options only when a user is logged in. User means werknemer in my language. In my login function I made this session:

$_SESSION['werknemer_level'] = 1; 

When no user(werknemer) is logged in, nothing shows on the header which is good. But when I log in with a werknemer account it still shows nothing in the header.

These are the if issets in my header:

<li><?php  if(isset($_SESSION['werknemer_level']) &&  $_SESSION['werknemer_level'] == 1): ?> <a href="">Uitgeplaatste jongeren</a><?php endif;?> </li>
                <li><?php  if(isset($_SESSION['werknemer_level']) &&  $_SESSION['werknemer_level'] == 1): ?><a href="">Ingeschreven jongeren</a><?php endif;?></li>
                <li><?php  if(isset($_SESSION['werknemer_level']) &&  $_SESSION['werknemer_level'] == 1): ?><a href="">Leeftijd jongeren</a><?php endif;?></li>
                <li><?php  if(isset($_SESSION['werknemer_level']) &&  $_SESSION['werknemer_level'] == 1): ?><a href="">Jongeren activiteiten</a><?php endif;?></li>
                <li><?php  if(isset($_SESSION['werknemer_level']) &&  $_SESSION['werknemer_level'] == 1): ?><a href="Auth/logout">Uitloggen</a><?php endif;?></li>

Does anyone know how to fix this problem and show al the li's when a user(werknemer) is logged in? Any kind of help is appreciated