Add additional fields in MUA membership sign up form

The MUA officers and Committee would like to have two additional fields to the MUA registration form (and, thus, invoice):

1) "Attention". This field is a multi-line text field. It can contain additional organizational information that is pertinent to the registrant (budget line information needed for billing, a name of a colleague in a particular office required for registration, etc.). It should appear after Country in the registration form. It should display after Country in the invoice.

2) "Reference". This field is a single-line text field. It can contain PO or other billing information. It should appear after Attention in the registration page and under the Invoice Number in the invoice.

Thank you,
Fritz Vandover (MUA Treasurer)