function stori_es_validate_apikey_callback()
{
    global $HttpHeaders;
    if (isset($_POST['api_key']) && stori_es_validate_apiurl_callback(true) == STORI_ES_API_SUCCESS) {
        $lHttpHeaders = $HttpHeaders;
        $lHttpHeaders[1] = 'Authorization: BASIC ' . $_POST['api_key'];
        $api_url = stori_es_correct_api_url($_POST['api_url']);
        // GET /users/self JSON to confirm API access
        $CurlRequest = new CurlRequest();
        $CurlRequest->setHttpHeaders($lHttpHeaders);
        $CurlRequest->createCurl($api_url . 'users/self');
        $objUser = json_decode($CurlRequest->getContent());
        echo $objUser->meta->status;
        // return value to ajax script
    } else {
        echo STORI_ES_API_INVALID;
    }
    wp_die();
}