NOTE:  You will be asked for your CVV2 code - that is the 3 digit security code from the back of your credit card.  There will also be a field for CVV2 Indicator (it is set to PRESENT) - that is asking if there is a code on your card or not.  If your code is illegible or non-existent please select the appropriate option from the dropdown box. 

ALSO:  The payment form asks for an invoice number.  For this type of transaction you do not need to enter one - that is only for people making payments on their account.