Adding a number to a set value

[ImJustBrndn]

I have a shopping cart system set up and I want to have a button that adds $4.00 to the total if the shipment is going international. I would like to know if there is a "add" command or something like that, that I can have this button point to, to add $4.00 to the total value of the shipment. This is the cart code as far as the money values go.

                        $totalvalue = $totalvalue + ($item["price"]*$ses_quan);
$subtotal = ($item["price"]*$ses_quan);
$shipping = 3.50 + ($totalvalue / 18.00 * 1.00);
$finalvalue = $totalvalue + $shipping

I would like to add $4.00 only on international shipments. Can someone tell me how to go about it and if there is a way to add that as a variable like..  $finalvalue = $totalvalue + $shipping + $international .... But how would I get it to figure the variable international bc I only want it to be $4.00 on certain shipments. Thanks in advance.

Brandon

[radar]

The way I would do it -- depending on the cart system -- is look where it defines the tax rate..  then after the tax rate is figured out throw something like this..

if ($location == "international") {
$shipping = ($shipping) + ('4.00');
}

Something similar should work...

[ImJustBrndn]

Ok thanks alot man.

[Jenk]

can also do[code]<?php

$var += 4;

?>[/code]