We are setting up a new installation. We want to show a checkbox and the line "Use different shipping address" in our one page checkout. When the user clicks the checkbox, the cart will open up additional fields to be filled in, otherwise those fields will remain hidden. The code for this isn't showing up in the default template, though it is shown on the examples here: http://www.foxycart.com/features/feature/checkout
What code will we need in our custom checkout to provide that feature?