[mmoskva]

On the cart/order pages the subtotal is displayed by:
{include file="currency.tpl" value=$cart.display_subtotal}
{include file="currency.tpl" value=$order.subtotal}


How do I add another calculation for SUBTOTAL (call it) SUBTOTALGC?


ex.
subtotalgc, would take the subtotal and also subtract any ⌠discount/coupon■ that was submitted.

IF customer has:

subtotal = $20.00
disount/coupon = -$2.00

THEN

subtotalgc =$18.00



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so I would have an additional field created:
{include file="currency.tpl" value=$cart.display_subtotalgc}
{include file="currency.tpl" value=$order.subtotalgc}
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