make a change to index.php file to calculate the discount amount and discount percent

[answerhappygod]

make a change to index.php file to calculate the discount amountand discount percent
<?php
$customer_type = filter_input(INPUT_POST, 'type');$invoice_subtotal = filter_input(INPUT_POST, 'subtotal');
if ($customer_type == 'R') {if ($invoice_subtotal < 100) {$discount_percent = .0;} else if ($invoice_subtotal >= 100 && $invoice_subtotal< 250) {$discount_percent = .1;} else if ($invoice_subtotal >= 250) {$discount_percent = .25;}} else if ($customer_type == 'C') {if ($invoice_subtotal < 250) {$discount_percent = .2;} else {$discount_percent = .3;}} else {$discount_percent = .0;}
$discount_amount = $invoice_subtotal * $discount_percent;$invoice_total = $invoice_subtotal - $discount_amount;
$percent = number_format(($discount_percent * 100));$discount = number_format($discount_amount, 2);$total = number_format($invoice_total, 2);
include 'invoice_total.php';
?>