SESSION destroys after POST
<p>I'm developing a site for someone where users can post problems to a website and the Admin of the company can view the problems and give a solution for it. I use one page that takes care of the login handling and a mysql db. The problem is that i can log in, it shows me another panel(userpanel), but whatever other button i click, it takes me back to the login panel.
It used to work as i was able to post data to my database. but suddenly after some changes on my website, it stopped working (and i can't find the problem anymore.)</p>

<p>When i log in, $_SESSION["LoggedIn"] gets a value and goes to the other panel on the same page with http post. when i click a button there, it seems that $_SESSION["LoggedIn"] is removed again because i check with isset if the user is logged in, otherwise it shows the userpanel.</p>

<pre><code>//check user logged in
if (isset($_SESSION['LoggedIn'])) {

//Problem posted
if (isset($_POST["plaatsen"])) {
    //Processing - plaatsen
    postProblem();
    }
} else {
//do login thing
</code></pre>

<p>}</p>

<p>I've attached my code here and i hope anyone can help me out.</p>

<p>Index.php: <a href="http://pastebin.com/BZSirUTT" rel="nofollow">http://pastebin.com/BZSirUTT</a></p>

<p>Functions.php: <a href="http://pastebin.com/7Hknhm9r" rel="nofollow">http://pastebin.com/7Hknhm9r</a></p>

<p>Website: <a href="http://php.olvgroeninge.be/~sac.26A-07/php/Oefeningen/Oefening3/index.php" rel="nofollow">http://php.olvgroeninge.be/~sac.26A-07/php/Oefeningen/Oefening3/index.php</a> (it's in dutch)</p>
