I'm trying to make a multiple languages. I followed the steps described here:http://www.concrete5.org/documentation/how-tos/editors/building-sit...

After the last step I get a fatal error: Call to undefined method Area::getCollectionAttributeValue()

I can't figure out what I'm doing wrong (quit new on this).
Could anyone help please?

My code looks like this:
<div id="topmenu">
<?php
$nav = new Area('Top Menu');
$nav->setBlockLimit(1);
if($nav->getCollectionAttributeValue('english_menus')) { $block = Block::getByName('English Menus'); if( is_object($block) ) $block->display(); } else { $block = Block::getByName('Dutch Menus'); if( is_object($block) ) $block->display(); }
?>
</div>