Subtract currency upon adopting

[Abronsyth]

Resolved

Now a mod-- Click!

OK, so I'm trying to essentially copy the files adoptview.php, adopt.php, and lang_adopt.php in order to create more adoption centers such as these because I'm able to individually customize the stores a lot more then.

However I've run into a road block. I don't know how to make it, when using these files, so that when a user "adopts" a cat that has a cost set to it, it subtracts the cost from the user's amount of currency. I can see where it happens in the shop files, but I'm not sure how to convert that over to the adopt files.

I think this is the function I need, but I don't know how to include/implement it in the shopname.php or shopnameview.php files (which are just versions of the adopt.php and adoptview.php files);

PHP Code:

    public function purchase($adopt){
        $mysidia = Registry::get("mysidia");
        if($adopt->owner != $mysidia->user->username) Throw new NoPermissionException('Something is very very wrong, please contact an admin asap.');
        else{
            $cost = $adopt->getcost($this->salestax);
            $moneyleft = $mysidia->user->money - $cost;
            if($moneyleft >= 0){    
                $purchase = $adopt->append($adopt->owner);
                $mysidia->db->update("users", array("money" => $moneyleft), "username = '{$adopt->owner}'");
                $status = TRUE;
            }            
            else throw new InvalidActionException($mysidia->lang->money);
        }
        return $status;
    } 


Would anyone be able/willing to help with this?