Set up Receipt Verification script (in PHP) from Fortumo.com to work on my Server and CS Cart.

I need someone to set up receipt verification script (in PHP) from [login to view URL] to work on my server and communicate with my CS Cart database. When someone completes a payment, [login to view URL] will inform my server by making a HTTP GET request to the URL that was specified in my service configuration (for example [login to view URL]). The payment processor script is written in PHP. This response is considered successful and notification delivered if my server responds with code 200. This receipt verification script is for integrating in-app purchases with users’ profile . The Receipt Verification script (hosted on my server) is called whenever a user makes a payment. The script first makes security checks (validate IP addresses, check the signature) to validate that the request came from Fortumo. Then the script processes the $_GET['product_name'] and $_GET['status'] parameters and grants virtual items to the user who made the purchase. Fortumo Mobile Payments for Web Apps integration is designed to be extremely simple and straightforward. The payment flow uses Premium SMS messages and HTTP requests to process payments. Payment is considered to be successful after Fortumo server has sent HTTP request to my receipt verification URL on my server. After my server has received the request from Fortumo with payment status=completed my backend should notify my frontend of successful payment and grant virtual goods to the end-user. The virtual goods will be in the form of virtual credits to the user in my CS Cart shopping cart. SAMPLE SCRIPT <?php // check that the request comes from Fortumo server if(!in_array($_SERVER['REMOTE_ADDR'], array('[login to view URL]', '[login to view URL]', '[login to view URL]', '[login to view URL]', '[login to view URL]', '[login to view URL]', '[login to view URL]'))) { header("HTTP/1.0 403 Forbidden"); die("Error: Unknown IP"); } // check the signature $secret = ''; // insert your secret between '' if(empty($secret) || !check_signature($_GET, $secret)) { header("HTTP/1.0 404 Not Found"); die("Error: Invalid signature"); } $sender = $_GET['sender'];//phone num. $amount = $_GET['amount'];//credit $cuid = $_GET['cuid'];//resource i.e. user $payment_id = $_GET['payment_id'];//unique id $test = $_GET['test']; // this parameter is present only when the payment is a test payment, it's value is either 'ok' or 'fail' //hint: find or create payment by payment_id //additional parameters: operator, price, user_share, country if(preg_match("/failed/i", $_GET['status'])) { // mark payment as failed } else { // mark payment successful } // print out the reply if($test){ echo('TEST OK'); } else { echo('OK'); } function check_signature($params_array, $secret) { ksort($params_array); $str = ''; foreach ($params_array as $k=>$v) { if($k != 'sig') { $str .= "$k=$v"; } } $str .= $secret; $signature = md5($str); return ($params_array['sig'] == $signature); } ?>