if you add:
php:
||<?php echo $_GET['Sitzungszimmer']; ?>||<?php echo $_SESSION['Sitzungszimmer']; ?>||
to the body of the page, what does that return?
If one of the get variables is missing is wouldn't expect it to work, there is no way for it to know what is selectedf in the parent list, etc...
you could force a default value using isset if you like, for example:
php:
<?php echo((isset($_GET['Sitzungszimmer'])?$_GET['Sitzungszimmer']:1); ?>
this will use the value of the GET Variable if it exists or 1 if not.
