Замена символов в php

$news_news = $data['news_breaks'] == "y" ? nl2br(stripslashes($data['news_news'])) : stripslashes($data['news_news']);
$news_full = $data['news_extended'] == "y" ? nl2br(stripslashes($data['news_extended'])) : stripslashes($data['news_extended']);
/////
echo " <item>
";
echo "<title>".$data['news_subject']."</title>
";
echo "<link>".$settings['siteurl']."news.php?readmore=".$data['news_id']."</link>
";
echo "<description><![CDATA[".$news_news."]]></description>";
echo "".$news_full."
";

echo htmlspecialchars('строка');

function replace_symbols($s)
{
$s = str_replace('&', '&amp;', $s);
$s = str_replace('<', '&lt;', $s);
$s = str_replace('>', '&gt;', $s);
$s = str_replace("'", '&apos;', $s);
return str_replace('"', '&quot;', $s);
}

echo "<description><![CDATA[".$news_news."]]></description>";
echo "".$news_full."

echo "<description><![CDATA[".replace_symbols($news_news)."]]></description>";
echo "".replace_symbols($news_full)."

.................
...............
...............
/////////////////
$result = dbquery("SELECT news_datestamp FROM ".DB_NEWS." ORDER BY news_datestamp DESC LIMIT 0,1");
$data = dbarray($result);
$build_date=$data['news_datestamp'];
$upldt = date("r",$build_date);// конвертация даты в формат RFC 2822

............
............
............



while ($data = dbarray($result))
{
/////
$news_news = $data['news_breaks'] == "y" ? nl2br(stripslashes($data['news_news'])) : stripslashes($data['news_news']);
$news_full = $data['news_extended'] == "y" ? nl2br(stripslashes($data['news_extended'])) : stripslashes($data['news_extended']);
/////
echo " <item>
";
echo "<title>".$data['news_subject']."</title>
";
echo "<link>".$settings['siteurl']."news.php?readmore=".$data['news_id']."</link>
";
echo "<description><![CDATA[".$news_news."]]></description>
";
echo "<author>".$data['user_name']."</author>
";
echo "<category>".$data['news_cat_name']."</category>
";
/////
$nd = $data['news_datestamp'];
$updt = date("r",$nd);
////
echo "<pubDate>".$updt."</pubDate>
";
echo "<yandex:full-text>".$news_full."</yandex:full-text>
";
echo "</item>
";
}

echo "</channel>
";
echo "</rss>";?>

error_reporting(E_ALL);

echo replace_symbols($переменная которая идет на вывод);

echo "<description><![CDATA[".$news_news."]]></description>";

echo "<description><![CDATA[".htmlspecialchars(stripslashes($news_news), ENT_QUOTES)."]]></description>";