Thanks! The single-image aspect of this appears to be working, and the Contacts page works, but not the Marshals one (index.php?main_page=index&cPath=1).

I do want to have the special background appear on certain EZpages only, so I added that additional code as well, although I'm not sure if it's in the right spot since I don't know PHP. I'm also not sure what to put into the code below to specify the EZpage I want, Author Biography (index.php?main_page=page&id=5&chapter=0).

Here's what I have in tpl_main_page.php:
PHP Code:
<!--Smart Backgrounds-->
<?php $smart_image '';
if (
$current_page_base == 'page' and $_GET['id'] == 7) {
}
if (
in_array($current_page_base,explode(",",'contact_us,1')) ) {
  
$smart_image '_badge';
}
?>
<!--/Smart Backgrounds-->
<div id="mainWrapper" class="smartBG<?php echo $smart_image;?>">
Here's what's in the stylesheet_smartbg.css file:
PHP Code:
#mainWrapper.smartBG_badge { background-image: url(../images/smartbg_badge.gif);}