public static function logIn(){
        $request = \Slim\Slim::getInstance()->request();
        // Since the request is in JSON format, we need to decode it
        $user = json_decode($request->getBody());
        // the rest of the code is just PDO stuff
        $sql = "SELECT id, passkey FROM users WHERE username=:username AND password=:password";
        try{
            $db = getConnection();
            $stmt=$db->prepare($sql);
            $stmt->bindParam(":username", $user->username);
            $stmt->bindParam(":password", md5sum($user->password + "salt"));
            $stmt->execute();
            $db = null;
            $row=$stmt->fetchAll(PDO::FETCH_OBJ);
            // here we check if there are rows
            if($row){
                echo '{"user":'.json_encode($row).'}';
                //echo json_encode($row);
            }
            else{
                $errArray = array('passkey'=>'false');
                echo '{"user":'.json_encode($errArray).'}';
                //echo json_encode($errArray);
            }
        }
        catch(PDOException $e){
            echo $e->getMessage();
        }
    }