Ok. I've figured it out and figured I'll post the info for other people. It's actually quite simple. Verisign allows you to include the fields USER1 through USER10.
You can use these fields to pass variables to Verisign (verisign doesn't use the variables). You can then set verisign to POST, SILENT POST, and FORCED SILENT POST to return the variables to a cgi script. For example, after the user makes a purchase use the following script to email the variables to yourself:
<?php
##Get form variables for non-array items
$name = $POST['NAME'];
$amount = $POST['AMOUNT'];
$address = $POST['ADDRESS'];
$city = $POST['CITY'];
$state = $POST['STATE'];
$zip = $POST['ZIP'];
$phone = $POST['PHONE'];
$email = $POST['EMAIL'];
$user1 = $POST['USER1'];
$user2 = $POST['USER2'];
$user3 = $POST['USER3'];
$user4 = $POST['USER4'];
$user5 = $POST['USER5'];
$user6 = $POST['USER6'];
$user7 = $POST['USER7'];
$user8 = $POST['USER8'];
$user9 = $POST['USER9'];
$user10 = $POST['USER10'];
$result = $_POST['RESULT'];
if ($result == "0") {
$approvalcode = "This transaction has been approved and the credit card has been charged.";
$shortcode = "Transaction approved.";
}else {
$approvalcode = "This transaction has been declined and the credit card was NOT been charged. You can delete this message.";
$shortcode = "Transaction denied.";
}
$recipient = "gordonisgo@wherever.com";
$subject = "Conference Registration: $shortcode ";
$mailheader = "From: $email\n";
$mailheader .= "Reply-To: $email\n\n";
$message = "$approvalcode\n";
$message .= "Registrant's name: $name\n";
$message .= "Address: $address, $city, $state, $zip\n\n";
$message .= "Email: $email, Phone: $phone\n\n";
$message .= "$user1\n\n";
$message .= "Membership: $user2\n\n";
$message .= "Sessions Attending: $user3\n\n";
$message .= "$user4\n\n";
$message .= "$user5\n\n";
$message .= "$user6\n\n";
$message .= "$user7\n\n";
$message .= "$user8\n\n";
$message .= "$user9\n\n";
$message .= "$user10\n\n";
mail($recipient, $subject, $message, $mailheader) or die ("Failure");
?>