OGP-Website/modules/modulemanager/navigation.xml

<navigation>
  <page key="add" file="add_module.php" access="admin" />
  <page key="del" file="delete_module.php" access="admin" />
  <page key="update" file="update_modules.php" access="admin" />
  <page key="default" file="modulemanager.php" access="admin" />
</navigation>