Determine if there are photos available for slideshow

I have customized my theme and added a link for slideshows. I added this link on the breadcrumb and system links line at the top of my site. Here http://www.markandtracy.net/v/Album/2008/August/ is an example page where I added the "** View as Slideshow **" link.

I want the link to only display if there are actually pictures available for the slideshow. How do I add an IF statement to check for this? Here is the code I currently am using. I am checking if the theme has a parent items so the slideshow link will not show on my home page.

      <div id="gsNavBar" class="gcBorder1">
	<div class="gbSystemLinks">
          {if not empty($theme.parents)}
            <a href="./slideshow.html">** View as Slideshow **</a>
          {/if}
	  {g->block type="core.SystemLinks"
		    order="core.SiteAdmin core.YourAccount core.Login core.Logout"
		    othersAt=4}
	</div>
	<div class="gbBreadCrumb">
	  {g->block type="core.BreadCrumb"}	  
	</div>
      </div>