$response
$response :
The variable to keep the response in until output
Provides a standard to base all responses to be called with AJAX on
http_response_code(integer  $code = null) : integer|boolean
                Get or set the HTTP response code
If a parameter is provided, it is used as the new HTTP response code, and a bool is returned for success or failure. Otherwise, the current one is returned.
| integer | $code | The new code  | 
                            
True on successful change, false on unsuccesful change, int when the current code is returned