echo '<pre>';
print_r($_POST);
$first = $_POST['first-number'];
$second = $_POST['second-number'];
$button = $_POST['btn'];
if ($button == 'add') {
$add = $obj->add($first, $second);
}
if ($button == 'sub') {
$add = $obj->sub($first, $second);
}
if ($button == 'mul') {
$add = $obj->mul($first, $second);
}
if ($button == 'div') {
$add = $obj->div($first, $second);
}
if ($button == 'mod') {
$add = $obj->mod($first, $second);
}
?>
<html>
<head>
<title>Calculator</title>
</head>
<body>
<form action="#" method="POST">
<table align="center" bgcolor="pink">
<tr>