protected function curl()
{
/* # set url addres */
curl_setopt($this->curl, CURLOPT_URL, $this->url);
curl_setopt($this->curl, CURLOPT_TIMEOUT, 5);
curl_setopt($this->curl, CURLOPT_HEADER, false);
curl_setopt($this->curl, CURLOPT_RETURNTRANSFER, true);
curl_setopt($this->curl, CURLOPT_NOBODY, true);
curl_setopt($this->curl, CURLOPT_POST, true);
curl_setopt($this->curl, CURLOPT_POSTFIELDS, $this->param);
return curl_exec($this->curl);
}