<?php
    header('Control-Allow-Origin: *');
    header('Access-Control-Allow-Origin: *');

    $url = 'http://www.russianpost.ru/autotarif/Autotarif.aspx';
    $params = '?viewPost=26&countryCode=643&typePost=1';
    $params .= '&weight=' . $_GET['weight'];
    $params .= '&value1=' . $_GET['value1'];
    $params .= '&postOfficeId=' . $_GET['postOfficeId'];
    $html = file_get_contents($url.$params);

    preg_match('/<input id="key" name="key" value="([0-9]+)"\/>/', $html, $matches);
    if ($matches) {
        $context = stream_context_create(array(
            'http' => array(
                'method' => 'POST',
                'header' => 'Content-Type: application/x-www-form-urlencoded' . PHP_EOL,
                'content' => 'key=' . $matches[1],
            ),
        ));

        $html = file_get_contents($url, false, $context);
    }

    preg_match('/<span id="lblErrStr">(.*)<\/span>/', $html, $error);
    if (!empty($error[1])) {
        echo $error[1];
    } else {
        preg_match('/<span id="TarifValue">([0-9,]+)<\/span>/', $html, $result);
        echo str_replace(',', '.', $result[1]);
    }
?>