Credit Card Verification

FormCGI enables you to verify the validity of credit card numbers.

Valid credit card numbers must match a specific set of equations. When a user provides a card number, FormCGI uses a modulo process to determine whether these equations are matched. If the user provides an invalid card number, a message is displayed identifying the error, together with a link back to the form. Alternatively, you may provide your own custom error page.

This feature is intended to identify common typos and mistakes. It does not verify that the card number is genuine, or that the card can be charged. Nor does it provide the ability to charge the card.

FormCGI currently supports American Express, Discover, MasterCard and Visa cards.

Enabling Credit Card Verification Parameters

Credit card verification is enabled by adding four fields to your form. These fields should use the following parameters.

The "cc_name" Parameter

A text field for the name of the cardholder:

<INPUT TYPE="text" NAME="cc_name">

The "cc_type" Parameter

A select list containing the different credit card values. You may include additional payment methods to this list. Credit card verification will only be invoked if a supported card value is selected (one of the first four options in the following example):

<SELECT NAME="cc_type">
<OPTION NAME="amex">American Express</OPTION>
<OPTION NAME="discover">Discover</OPTION>
<OPTION NAME="mastercard">MasterCard</OPTION>
<OPTION NAME="visa">Visa</OPTION>
<OPTION NAME="money_order">Money Order</OPTION>
<OPTION NAME="personal_check">Personal Check</OPTION>
</SELECT>

The "cc_number" Parameter

A text field for the credit card number:

<INPUT TYPE="text" NAME="cc_number">

The "cc_exp" Parameter

 A text field for the credit card expiration date:

<INPUT TYPE="text" NAME="cc_exp">

Providing a Custom Error Page

By default, when a user provides an invalid card number, a message is displayed identifying the error, together with a link back to the form. Alternatively, you may provide your own custom error page with the "bad_cc_redirect" parameter as follows (replacing "yourname" and "yourchoice" as appropriate):

<INPUT TYPE="hidden" NAME="bad_cc_redirect"
VALUE="http://www.yourname.com/yourchoice.html">