On your confirmation email you have login information to log into the Attendee Service Center. You will login and "Edit Registration" then "edit" again to the right of your name. Continue through until you see the ancillary page(proceedings will be listed on the registration fee page), there are tabs on this page listing all the ancillary items. Click on the appropriate icon and it will list the available items. Continue through to the payment page. If you added an ancillary item with a waiver form, this will listed on the last page. Upon completion of payment you will receive a new confirmation with the items added listed. If you need further assistance please feel free to contact us.