Facebook Javascript: display more posts on the wall

I am creating a Chrome extension which has a Javascript modifying Facebook page layout, how can I make the wall displaying older posts?

I've tried injecting a script into the page and calling the function

UIIntentionalStream.instance.loadOlderPosts()

but it's not working since the script doesn't get called (my script runs after the entire page has been loaded).

I can't figure out how to expand wall to display older posts programatically with Javascript, can someone help please?