Only show current month of post in wordpress

<?php $current_month = date('m'); ?>

<?php $current_year = date('Y'); ?>

<?php query_posts("monthnum=$current_month&year=$current_year") ?>

<?php if ( have_posts() ) : ?>

<?php while ( have_posts() ) : the_post(); ?>

<?php the_content(); ?>

<?php endwhile; ?>

<?php else : ?>

<?php endif; ?>