PHP Last.FM Get RSS Feed

<?php
$username = '';
$feed_url = 'http://ws.audioscrobbler.com/1.0/user/' . $username . '/recenttracks.rss';
$content = file_get_contents($feed_url);
$x = new SimpleXmlElement($content);
echo "<ul>";
foreach($x->channel->item as $entry) {
    echo '<div id="latest" align="center" style="margin-left: -35px;">' . "<li><a href='$entry->link' title='$entry->title'>" . $entry->title . "</a></li>" . '</div>';
}
echo "</ul>";
?>