How do I copy address info with the check box "same as"

On the confirm page I had to add the fields company and department to invoice and shipping information. The little check box "same as" is supposed to copy the information from the invoice info to the shipping info. But it doesn't work for the two new fields I added. Would anybody know where I have to change the code to make this happen?

in the WA_eCart/scripts/copyShipping.js file, there are two arrays created. One contains all of the frm elements in the builling section of the form:
var billingFields = new Array('firstname', 'lastname', 'email', 'phone', 'fax', 'street1', 'street2', 'city', 'state_province', 'postcode', 'country');

the other contains the corresponding shipping form elements:
var shippingFields = new Array('shipping_firstname', 'shipping_lastname', 'shipping_email', 'shipping_phone', 'shipping_fax', 'shipping_street1', 'shipping_street2', 'shipping_city', 'shipping_state_province', 'shipping_postcode', 'shipping_country');


you need to add your new fields to the list:
var billingFields = new Array('firstname', 'lastname', 'email', 'phone', 'fax', 'street1', 'street2', 'city', 'state_province', 'postcode', 'country', 'newBilling1', 'newBilling2');

var shippingFields = new Array('shipping_firstname', 'shipping_lastname', 'shipping_email', 'shipping_phone', 'shipping_fax', 'shipping_street1', 'shipping_street2', 'shipping_city', 'shipping_state_province', 'shipping_postcode', 'shipping_country', 'newSshipping1', 'newShipping2');

Thank you Jason, it worked! It was so easy, if I only knew where to look.