WordPress/wp-content/themes/twentyten/sidebar-footer.php

<?php
	if ( 
		is_active_sidebar( 'first-footer-widget-area' )  ||
		is_active_sidebar( 'second-footer-widget-area' ) ||
		is_active_sidebar( 'third-footer-widget-area' )  ||
		is_active_sidebar( 'fourth-footer-widget-area' ) 
	) :
?>
			<div id="footer-widget-area">
<?php if ( is_active_sidebar( 'first-footer-widget-area' ) ) : ?>
					<div id="first" class="widget-area">
						<ul class="xoxo">
							<?php dynamic_sidebar( 'first-footer-widget-area' ); ?>
						</ul>
					</div><!-- #first .widget-area -->
<?php endif; ?>

<?php if ( is_active_sidebar( 'second-footer-widget-area' ) ) : ?>
				<div id="second" class="widget-area">
					<ul class="xoxo">
						<?php dynamic_sidebar( 'second-footer-widget-area' ); ?>
					</ul>
				</div><!-- #second .widget-area -->
<?php endif; ?>

<?php if ( is_active_sidebar( 'third-footer-widget-area' ) ) : ?>
				<div id="third" class="widget-area">
					<ul class="xoxo">
						<?php dynamic_sidebar( 'third-footer-widget-area' ); ?>
					</ul>
				</div><!-- #third .widget-area -->
<?php endif; ?>

<?php if ( is_active_sidebar( 'fourth-footer-widget-area' ) ) : ?>
				<div id="fourth" class="widget-area">
					<ul class="xoxo">
						<?php dynamic_sidebar( 'fourth-footer-widget-area' ); ?>
					</ul>
				</div><!-- #fourth .widget-area -->
<?php endif; ?>

			</div><!-- #footer-widget-area -->
<?php endif; ?>