you would need to write a loop through the cart items, with an update statement to lookup the item ID and update the Stock Column
<?php
$eCart1->MoveFirst();
while (!$eCart1->EOF()) {
<lookup the item ID using $eCart1->DisplayInfo("ID") to return the available qty>
<update the AvailableQuantity - Quantity Ordered>
$eCart1->MoveNext();
}
$eCart1->MoveFirst();
?>
The exact specifics for implementing this depend on the gate way being used, if you need help with this, we can help in a premiere support appointment:
http://www.webassist.com/premier_request.php
