[@kawauso Member 15 years, 4 months ago]

Right.

In topics.php, delete:

<?php if ( topic_is_open( $bb_post->topic_id ) ) : ?>

<?php post_form(); ?>

<?php else : ?>

<h2><?php _e('Topic Closed') ?></h2>

<p><?php _e('This topic has been closed to new replies.') ?></p>

<?php endif; ?>

Then after the first <?php topic_pages( array( 'before' => '<div class="nav">', 'after' => '</div>' ) ); ?>, insert:

<?php if ( $page === 1 ) : ?>

<?php if ( topic_is_open( $bb_post->topic_id ) ) : ?>

<?php post_form( array( 'last_page_only' => false ) ); ?>

<?php else : ?>

<h2><?php _e('Topic Closed') ?></h2>

<p><?php _e('This topic has been closed to new replies.') ?></p>

<?php endif; ?>

<?php endif; ?>

It’ll be different if you’re using something that’s radically different to Kakumei, but the general idea is to take the bit that looks something like the first part and put <?php if ( $page === 1 ) : ?> and <?php endif; ?> around it, change post_form() to post_form( array( 'last_page_only' => false ) ) then move it to the top of the page.