function addAuthor( $id, $name, $email )
    {
        if ( $id == -1 )
        {
            if ( isset( $this->Authors[$this->AuthorCount - 1] ) )
                $id = $this->Authors[$this->AuthorCount - 1]['id'] + 1;
            else
                $id = 1;
        }

        $this->Authors[] = array( "id" => $id,
                                  "name" => $name,
                                  "email" => $email,
                             "is_default" => false );

        $this->AuthorCount ++;
    }