$postdata = http_build_query(
	array(
		'numg' => $numG,
		'nump' => $numP,
		'password' => $pass
	)
);

$opts = array(
	'ssl' =>
	array(
		'verify_peer' => false,
		'verify_peer_name' => false,
	),
	'http' =>
	array(
		'method' => 'POST',
		'header' => 'Content-type: application/x-www-form-urlencoded',
		'content' => $postdata
	)
);

$context = stream_context_create($opts);
$contents = file_get_contents($url, false, $context);

$xml = simplexml_load_string(html_entity_decode($contents));
if ($xml === false) {
	echo "Error cargando XML\n";
	foreach (libxml_get_errors() as $error) {
		echo "\t", $error->message;
	}
}