Trouble with conditional category tags in index page

I’m trying to create a tumblelog based on these instructions at Openswitch and I can’t even get past the first bit of code. I am using a slightly modified version of the Tiny theme, which I’d like to modify further into a tumblelog format.

My index looks like this:

<?php
// index.php
// Tiny theme for WordPress
// Copyright (C) 2005 Ben de Groot
// Distributed under the terms of the GNU General Public License v2

get_header();
// Check if the sitemap is requested
if ( isset($_GET['sitemap']) ) {
	include('sitemap.php');

} else {

if (have_posts()) : while (have_posts()) : the_post();

?>

<h2 id="post-<?php the_ID(); ?>"><a href="<?php the_permalink() ?>" rel="bookmark" title="<?php _e('Permanent Link','bnTiny'); ?>: <?php the_title(); ?>"><?php the_title(); ?></a></h2>

<p class="posted"><?php the_date('', '', ' at', TRUE); ?> <?php the_time(); ?> | <?php the_category(', '); ?> | <?php comments_popup_link( __('No Comments','bnTiny'), __('1 Comment','bnTiny'), __('% Comments','bnTiny') ); ?>

<?php edit_post_link($link = __('Edit','bnTiny'), $before = ' | ', $after = ''); ?></p>

<?php the_content(); ?><br />

<?php endwhile; ?>

<p class="nav"><span class="prev"><?php posts_nav_link( '', '', __('« Previous Entries','bnTiny') ) ?></span>

<span class="next"><?php posts_nav_link( '', __('Next Entries »','bnTiny'), '' ) ?></span></p>	

<?php else: ?>

<p><?php _e('Sorry, nothing found.','bnTiny'); ?></p>

<?php endif; ?>

<?php

}

get_footer(); ?>

I am trying to paste the first conditional code:

<?php if ( in_category(4) && !is_single() ) : ?>

<div class=“post”>

<span class=“permalink”> <a href=”<?php the_permalink() ?>” rel=“bookmark” title=“Permanent Link to <?php the_title(); ?>”>¶</a></span>

<div class=“post_body”>

<div class=“conversation”>

<?php the_content(); ?>

</div>

</div>

</div>

in there somewhere but no matter where I put it I come up with a syntax error. I don’t know a whole lot about PHP but I thought I knew more than this. Help please!