Showin gallery prev/next links IF necessary

Hi,

What I need is for the ability to show or hide a <div> containing my next/prev controls for image galleries depending on whether or not there’re actually any other images. At the moment I have this:

<?php if ( previous_image_link() != null || next_image_link() != null ) { ?>
<div class="page_controls">
	<div class="wp-caption alignleft">
<?php previous_image_link() ?>
	</div>
	<div class="wp-caption alignright">
<?php next_image_link() ?>
	</div>
</div>
<?php } ?>

But this isn’t working. It echoes out the prev/next links as usual, but not all the <div>s in my if statement.

I’m fairly sure my if statement is invalid, but I don’t know what to do to make this concept work. Hopefully my code is enough to demonstrate exactly what I’m after, though.

I really hope someone can help me out as I’ve torn my hair out for an hour trying to do this myself. :~