Using RC API with PHP

I wrote the following PHP code and I always obtain Response HTTP Status Code : 400 Response HTTP Body : 400 Bad Request400 Bad Request when I run it . What goes wrong:

// create curl resource
$ch = curl_init();
// set url
curl_setopt($ch, CURLOPT_URL, ‘https://myRCserver/api/v1/login -d “user=john&password=doe”’);

    //return the transfer as a string 
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); 

    // $resp contains the output string 
    $resp = curl_exec($ch); 
    if(!$resp) {
        die('Error: "' . curl_error($ch) . '" - Code: ' . curl_errno($ch));
      } else {
        echo "Response HTTP Status Code : " . curl_getinfo($ch, CURLINFO_HTTP_CODE);
        echo "\nResponse HTTP Body : " . $resp;
      }
    echo $resp ;

    // close curl resource to free up system resources 
    curl_close($ch);