theviewer1985 on "Make a div scroll down the page while I scroll..."

Hi

Please look at this example: http://himalayatorquay.co.uk

click the "Our Menu" link. Please then scroll down the page and see the cart on the right scrolls very smoothly along with you. (note: it might say "we are closed" depending on the time. But it still moves the same)

How would I do this in wordpress? Is there a plugin? Or any Jscripts I can use.

Thanks