I must particularly know in which the variables $product_parent_id and $product_id are originating from.

I've produced another file entitled addtocart_form2.tpl.php and would really like for this to see from the second group of variables (i.e. $product_parent_id2, $product_id2) I've attended shop.product_particulars.php and produced the variable $product_id2 as virtually another demonstration of $product_id, but up-to-date accordingly in the own group of database variables (in the event that makes sense at all).

Among the finest to understand where these variables are defined in order to affect the sources. Thanks

list($html,$children) = $ps_product_attribute->list_attribute( ( $product_parent_id > 0 )  ? $product_parent_id : $product_id );

$product_id and $product_parent_id will also be in shop.product_particulars.php

line 35:

$product_id = intval( vmGet($_REQUEST, "product_id", null) )

line 78:

$product_parent_id = (int)$db_product->f("product_parent_id")

(in VM 1.1.9)