I'm trying to send a message to the users. I use a message object but it doesn't work. Here is my code:

```
        $sAccessToken = $facebook->getAccessToken();
        $aParams = array(
            'method'=> 'message',
            'format' => 'post',
            'from'=> $sFrom,
            'to' => $aTo, 
            'message' => $sMessage,
            'access_token' => $sAccessToken,
        );
        $facebook->api($aParams);

```

I got only error with message: Unknown method 

Thx for help.