plugin_license decoded

<?php
define("POPUP_DOM_PATH", dirname(dirname(__FILE__)) . "/");
$cpath = POPUP_DOM_PATH . "install/";
require_once POPUP_DOM_PATH . "popup-domination.php";
$popdom = new PopUp_Domination();
$in     = $popdom->in();
if (count($_POST) > 0) {
    $arr       = array(
        "receipt_key"
    );
    $errormsg  = "";
    $show_form = true;
    $newarr    = array();
    foreach ($arr as $a) {
        $val        = trim($in[$a]);
        $newarr[$a] = $val;
    }
    foreach ($newarr as $a => $b) {
        ${$a} = $b;
    }
    $showform = true;
    $check    = $install = $failed = false;
    $key      = $receipt_key;
    if ($key == "PD2S0A1H2") {
        $install  = true;
        $showform = false;
        $code     = $popdom->resetcode();
        define("INSTALL_SESH_KEY", $code);
        header("Location: step2.php?step=" . INSTALL_SESH_KEY);
    } else {
        $chkurl = "http://www.popupdomination.com/thanks-secure/check_receipt.php?receipt_key=" . urlencode(base64_encode($_POST["receipt_key"])) . "&url=" . urlencode(base64_encode($url)) . "&type=plugin";
        if (function_exists("curl_init")) {
            $ch = curl_init();
            curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/5.0 (compatible; Konqueror/4.0; Microsoft Windows) KHTML/4.0.80 (like Gecko)");
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
            curl_setopt($ch, CURLOPT_URL, $chkurl);
            curl_setopt($ch, CURLOPT_HTTPGET, 1);
            curl_setopt($ch, CURLOPT_TIMEOUT, 60);
            $resp = curl_exec($ch);
//============================== PAYMENT ====================================//