php - Paypal PDT script not working using cURL -

i can't seem paypal pdt script working. paypal hits return url i'm presented blank screen , nothing happens. can see incorrect? here's code:

$tx = $_get['tx']; $id = $_get['cm']; $amount = $_get['amt']; $currency = $_get['cc']; $identity = '###########################################';   // init curl $ch = curl_init();   // set request options $url = 'https:www.paypal.com/cgi-bin/webscr'; $fields = array(     'cmd' => '_notify-synch',     'tx' => $tx,     'at' => $identity, );  curl_setopt($ch,curlopt_url, $url); curl_setopt($ch,curlopt_post, count($fields)); curl_setopt($ch,curlopt_postfields, $fields_string); curl_setopt($ch,curlopt_returntransfer, true); curl_setopt($ch,curlopt_header, false);  // execute request , response , status code $response = curl_exec($ch); $status   = curl_getinfo($ch, curlinfo_http_code);  // close connection curl_close($ch); if($status == 200 , strpos($response, 'success') === 0) {     wp_redirect(home_url('/account'));     exit; } else {     wp_redirect(home_url());     exit; } 

the url string shows necessary information being returned (transaction id etc) correct don't know if it's being used failing wordpress redirects or if it's failing @ point beforehand.

coreyrs,

using code able to pdt work few changes:

$url = 'https:www.paypal.com/cgi-bin/webscr'; 

to

$url = 'https://www.paypal.com/cgi-bin/webscr'; 

and

curl_setopt($ch,curlopt_postfields, $fields_string); 

to

curl_setopt($ch,curlopt_postfields, http_build_query($fields)); 

also, make sure if testing sandbox use url https://www.sandbox.paypal.com/cgi-bin/webscr instead.