Discount coupon off of Sales not Shipping and Sales

[batteryman]

Hello,

This is a two part question.

1. I was looking around in /public_html/includes/modules/checkout_process.php and I came across this bit of code and at line 88 there is a double $$. Should it be that way or should I remove one of the $?

$credits_applied = 0;
for ($i=0, $n=sizeof($order_totals); $i<$n; $i++) {
if ($order_totals[$i]['code'] == 'ot_subtotal') $order_subtotal = $order_totals[$i]['value'];
if ($$order_totals[$i]['code']->credit_class == true) $credits_applied += $order_totals[$i]['value'];
if ($order_totals[$i]['code'] == 'ot_total') $ototal = $order_totals[$i]['value'];

2. I want to change the discount coupon to only remove whatever the incentive is off of the products being purchased and not the entire amount that includes the shipping.

How would I accomplish this??

Thank you,

Avel