I have a form with lots of check boxes in it that when you check the checkbox the from sends through the value "on". Before I insert them into my database I want to change these to something more usable like the value "Yes" and then for all the boxes that weren't checked the value is "No". Can someone help me with that?

This is my code:

```
<?php

include_once 'database_login.php'; 

$barcode = $_POST['barcode'];
$name = $_POST['name'];
$company = $_POST['company'];
$fair_trade = $_POST['fair_trade'];
$palm_oil = $_POST['palm_oil'];
$organic = $_POST['organic'];
$gm_free = $_POST['gm_free'];
$nz = $_POST['nz'];
$animals = $_POST['animals'];
$recyclable = $_POST['recyclable'];
$category = $_POST['category'];
$sub_category = $_POST['sub_category'];

$add = "INSERT INTO products (barcode, name, company, fair_trade, palm_oil, organic,   gm_free, nz, animals, recyclable, category, sub_category) VALUES ('$barcode', '$name', '$company', '$fair_trade', '$palm_oil', '$organic', '$gm_free', '$nz', '$animals', '$recyclable', '$category', '$sub_category')";
$added = mysqli_query($con, $add);
header( "Location: add.php?message=1");

 mysqli_close($con);

?>

```