sidebar.php

<?php
?>
<?php if ( is_active_sidebar( 'sidebar' ) ) : ?>

<div id="blog-sidebar" role="complementary">
	<ul id="sidebar-widgets">
		<?php dynamic_sidebar( 'sidebar' ); ?>
	</ul>
</div>
<!-- #secondary -->

<?php 
		
// PHP request : If active sidebar doesn't have any widgets, load some by default. (I've seen this elsewhere)

		?>
<?php endif; ?>