You can change it so that the preview panel appears with your site layout.
Create a new template named my-comments-preview-tpl.php. Insert your page header, sidebar and footer HTML. Then copy the below code into the template.
In the head section of the page:
<?php require 'head-inc.php'; $separator = ($display['form_location']) ? '–' : ''; ?>
In the body section of the page:
<?php print " <div id='tb-wrapper'> <div class='tb-comment'> <div class='tb-comment-header'> <div class='tb-author-loc'> <span class='tb-author'>{$display['form_author']}</span> $separator <span class='tb-location'>{$display['form_location']}</span> </div> </div>"; if ($config['comment_subject']) // Show subject line print " <div class='tb-comment-subject'><span class='tb-subject-title'>{$lang['subject']}</span> {$display['form_subject']}</div>"; print " <div class='tb-comment-text'> {$display['form_textarea']} </div> </div> <br /><br />"; if ($_REQUEST['action'] == 'update') { require 'comments-edit-form-tpl.php'; } else { include $config['comments_form_tpl']; } print " </div> <!--end of tb-wrapper -->"; ?>
Finally, change the preview panel file name in the admin configuration settings panel.