<aside id="main-sidebar" class="primary-sidebar widget-area clearfix" role="complementary">
<?php
if ( is_active_sidebar( 'book_rev_lite_primary_sidebar' ) ) :
dynamic_sidebar('book_rev_lite_primary_sidebar');
else:
the_widget('WP_Widget_Archives');
the_widget('WP_Widget_Calendar');
the_widget('WP_Widget_Categories');
endif;
?>
</aside><!-- end #main-sidebar -->