2nd widget unusable

I have created 2 widget sidebars but they it won’t let me put anything in the 2nd sidebar. I have tried with multiple different widgets and none work. Below is my code from the function.php file.

<?php
if ( function_exists('register_sidebar') )
register_sidebar( array(
	'name' => 'Mid Column',
	'id' => 'mid',
	'before_widget' => '',
	'after_widget' => '',
	'before_title' => '',
	'after_title' => '',
) );
register_sidebar( array(
	'name' => 'Ads',
	'id' => 'ads',
	'before_widget' => '',
	'after_widget' => '',
	'before_title' => '',
	'after_title' => '',
) );

Within the code I have the sidebars called in the following manner

<div id="mainPageSidebar">
		    <?php if (!dynamic_sidebar("ads") ) : ?><?php endif; ?>
        </div>