From another forum I found the following example:
"I was looking for a way to pull node data via ajax and came up with the following solution for Drupal 6. After implementing the changes below, if you add ajax=1 in the URL (e.g. mysite.com/node/1?ajax=1), you'll get just the content and no page layout.
in the template.php file for your theme:
function phptemplate_preprocess_page(&$vars) {
if ( isset($_GET['ajax']) && $_GET['ajax'] == 1 ) {
$vars['template_file'] = 'page-ajax';
}
}
then create page-ajax.tpl.php in your theme directory with this content:
<?php print $content; ?>
"
This seems like the logical way to do it and I did this, but the phptemplate_preprocess_page function is never called ... any suggestions?