[php] "Headers already sent" error - hoe te voorkomen?

<?php include("forum/mods/phpbb_fetch_all/include_latestpostings.php");?>

<?php

//
// This path points to the directory where phpBB is installed. Do
// not enter an URL here. The path must end with a trailing
// slash.
//
// Examples:
// forum in /aaa/bbb/ccc/ and script in /aaa/bbb/ccc/
// --> $phpbb_root_path = './';
// forum in /aaa/bbb/ccc/ and script in /aaa/bbb/
// --> $phpbb_root_path = './ccc/';
// forum in /aaa/bbb/ccc/ and script in /aaa/bbb/ddd/
// --> $phpbb_root_path = '../ccc/';
//

$phpbb_root_path = 'forum/';

define ('IN_PHPBB', true);

if (!file_exists($phpbb_root_path . 'extension.inc'))
{
    die ('<tt><strong>phpBB Fetch All:</strong>
        $phpbb_root_path is wrong and does not point to your forum.</tt>');
}

//
// phpBB related files
//

include_once ($phpbb_root_path . 'extension.inc');
include_once ($phpbb_root_path . 'common.' . $phpEx);
include_once ($phpbb_root_path . 'includes/bbcode.' . $phpEx);

//
// Fetch All related files - we do need all these because the portal is a
// huge example
//

include_once ($phpbb_root_path . 'mods/phpbb_fetch_all/common.' . $phpEx);
include_once ($phpbb_root_path . 'mods/phpbb_fetch_all/posts.' . $phpEx);

//
// start session management
//

$userdata = session_pagestart($user_ip, PAGE_INDEX);
init_userprefs($userdata);

//
// since we are demonstrating span pages we need to set the page offset
//

if (isset($HTTP_GET_VARS['start']) or isset($HTTP_POST_VARS['start']))
{
    $CFG['posts_span_pages_offset'] = isset($HTTP_GET_VARS['start'])
    ? $HTTP_GET_VARS['start'] : $HTTP_POST_VARS['start'];
    if (!intval($CFG['posts_span_pages_offset']))
    {
        $CFG['posts_span_pages_offset'] = 0;
    }
    if (!is_numeric($CFG['posts_span_pages_offset']))
    {
        $CFG['posts_span_pages_offset'] = 0;
    }
    if ($CFG['posts_span_pages_offset'] < 0) {
        $CFG['posts_span_pages_offset'] = 0;
    }
}

// fetch latest postings
$CFG['posts_trim_topic_number'] = 60;
$recent = phpbb_fetch_posts(null, POSTS_FETCH_LAST);


//
// disconnect from the database
//

phpbb_disconnect();

?>
<?php if (isset($recent)) { ?>
<?php for ($i = 0; $i < count($recent); $i++) { ?>
<?php echo '<span class="latesttopics_date">';?>
<?php echo create_date($board_config['default_dateformat'], $recent[$i]['post_time'], $board_config['board_timezone']); ?>
<?php echo '</span>';?>
<?php echo '<span class="latesttopics_topic">';?>
<?php echo ':<br /><img src="http://www.alice-in-wonderland.net/layoutpics/topicarrow.gif" border="0" align="absmiddle" /> <a target="_blank" href="';?>
<?php echo append_sid($phpbb_root_path . 'viewtopic.php?p=' . $recent[$i]['post_id'] . '#' . $recent[$i]['post_id']); ?>
<?php echo '">';?>
<?php echo $recent[$i]['topic_title']; ?>
<?php if ($recent[$i]['topic_trimmed']) { echo '...'; } ?>
<?php echo '</a><br />';?>
<?php echo '</span>';?>
<?php } ?>
<?php } ?>

setcookie($cookiename . '_data', serialize($sessiondata), $current_time + 31536000, $cookiepath, $cookiedomain, $cookiesecure);
setcookie($cookiename . '_sid', $session_id, 0, $cookiepath, $cookiedomain, $cookiesecure);