unable to rsvp on meetup through API

Question

I am trying to update my rsvp status for an event, such as http://www.meetup.com/group/events/219126470/

$event_rsvp_url ="https://api.meetup.com/2/rsvp/?event_id=".$event_id."&key=".$this->meetup_api_key."&rsvp=no";
$curl_handle=curl_init();
curl_setopt($curl_handle, CURLOPT_URL, $event_rsvp_url);
curl_setopt($curl_handle, CURLOPT_CONNECTTIMEOUT, 2);
curl_setopt($curl_handle, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($curl_handle, CURLOPT_SSL_VERIFYPEER, 0);
curl_setopt($curl_handle, CURLOPT_USERAGENT, 'Your application name');
$query = curl_exec($curl_handle);
curl_close($curl_handle);
return $query;

this is all i am getting

string(0) ""

Answer 1

Turns out i was trying to get not post. This works for me.

/**
    * Send a POST requst using cURL
    * @param string $url to request
    * @param array $post values to send
    * @return string
    */
    function curl_post($url, array $post = NULL){
        $cURL = curl_init();
        curl_setopt($cURL, CURLOPT_URL, $url);
        curl_setopt($cURL, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($cURL, CURLOPT_SSL_VERIFYPEER, 0);
        curl_setopt($cURL, CURLOPT_POST, 1);
        curl_setopt($cURL, CURLOPT_POSTFIELDS, $post);  

        if(!$result = curl_exec($cURL)) {
            trigger_error(curl_error($cURL));
        }

        curl_close($cURL);
        return $result;
    } 

$post = array('event_id' => $event_id, 'key' => $api_key, 'rsvp' => 'yes', 'guests' => '0', 'member_id' => '9736856');
    $url = "https://api.meetup.com/2/rsvp/";   
    print_r($meetup->curl_post($url, $post));