<?php
$data = [
'zaloguj' => 'Ok',
'userid' => 'TWOJEID',
'haslo' => 'TWOJEHASŁO'
];
$c = curl_init();
curl_setopt($c, CURLOPT_URL, "http://xn.pl/index.php?strona=konto");
curl_setopt($c, CURLOPT_POST, 1);
curl_setopt($c, CURLOPT_POSTFIELDS, http_build_query($data));
curl_setopt($c, CURLOPT_RETURNTRANSFER, true);
curl_setopt($c, CURLOPT_FOLLOWLOCATION , true);
curl_setopt ($c, CURLOPT_USERAGENT, "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.6) Gecko/20070725 Firefox/2.0.0.6");
$page = curl_exec($c);
curl_close($c);
echo 'Wynik: <br>' .$page;
Jest mała różnica pomiędzy Ok a ok