using Purchase Order Contrib, email help needed

[Guest]

I have the PO contrib installed and I can use it to purchase an item. However when I get the confirmation email it says Purchase Order for the payment method but doesn't display the PO number used. In addition to putting this in there I would like to add that PO is net20 days.

 

The code from \catalog\checkout_process.php looks like it handles it, I just don't know how or what to put in

 

  $email_order .= "\n" . EMAIL_TEXT_BILLING_ADDRESS . "\n" .
                 EMAIL_SEPARATOR . "\n" .
                 tep_address_label($customer_id, $billto, 0, '', "\n") . "\n\n";
 if (is_object($$payment)) {
   $email_order .= EMAIL_TEXT_PAYMENT_METHOD . "\n" . 
                   EMAIL_SEPARATOR . "\n";
   $payment_class = $$payment;
   $email_order .= $payment_class->title . "\n\n";
   if ($payment_class->email_footer) { 
     $email_order .= $payment_class->email_footer . "\n\n";
   }

 

How would I go about doing this?