<!-- Collection of code snippets by Arne Vajhøj -->
<!-- created to try various things (2003-now) -->
<?php
header('Content-Type: application/json');
$o = json_decode(file_get_contents('php://input'));
$v1 = $o->v1;
$v2 = $o->v2;
$v3 = $v1 + $v2;
echo '{ "v3" : ' . $v3 . ' }';
?>