Wordpress query_posts and orderby page order

Question

I have a page that lists all sub pages of the current page. Each page has been assigned an order number in the wordpress editor but they aren't ordering for some reason.

I'm set up like this:

Products

-page1

-page2

-page3

-page4

-page5

my query_posts looks like this:

query_posts('post_type=page&order=ASC&orderby='.$post->menu_order.'&post_parent='.$post->ID);

But the output comes out like:

1,3,2,5,4

How do I simply order pages with the built in page order field? I thought this was default...