X-Cart/Smarty Custom PHP Scripts

i have what may be a very simple question for someone who has worked with X-Cart or Smarty.

I am adding a rollover image next to the category names in the main navigation. The following is my stripped down for this post version.

        
{foreach from=$categories item=c}

     <div>

          <div><img name="{$c.category}_" src="{$ImagesDir}/custom/paw.gif"></div>
          <div><a href="home.php?cat={$c.categoryid}">{$c.category}</a></div>

     </div>

{/foreach}

PHP:

I need to remove spaces in the names given at

name="{$c.category}_"

Code (markup):

I want to make it

name="{str_replace(" ","_",$c.category)}_"

Code (markup):

My attempts don't work and I get this error

My question is.. How can I make PHP functions work in X-Cart/Smarty?

I cant even find where $c.category is set. Thanks much.

 

Thanks Jay. Here's the solution-

{$c.category|replace:" ":""}

Code (markup):

im now finding that slashes are not allowed either.

{$c.category|replace:" ":""|replace:"/":""}

Code (markup):

works too. sweet.