public function post($url, $data = array())
{
$this->setopt(CURLOPT_URL, $url);
$this->setopt(CURLOPT_POST, true);
if (is_array($data) || is_object($data)) {
$data = http_build_query($data);
}
$this->setopt(CURLOPT_POSTFIELDS, $data);
$this->_exec();
}