Fatal error in comments.php file. Please help…

Hi,

I get an error at the bottom of:

https://www.skylinestyling.com/latest-fashion-trends/testing-post/#respond

It says: Fatal error: Call to undefined function: split_comments() in /wp-content/themes/premiumnews/comments.php on line 24

Here’s the code for the comments.php file:

<?php
global $wpdb;

$sql = "SELECT DISTINCT ID, post_title, post_password, comment_ID,
comment_post_ID, comment_author, comment_date_gmt, comment_approved,
comment_type,comment_author_url,
SUBSTRING(comment_content,1,50) AS com_excerpt
FROM $wpdb->comments
LEFT OUTER JOIN $wpdb->posts ON ($wpdb->comments.comment_post_ID =
$wpdb->posts.ID)
WHERE comment_approved = '1' AND comment_type = '' AND
post_password = ''
ORDER BY comment_date_gmt DESC LIMIT 5";

$comments = $wpdb->get_results($sql);
$output = $pre_HTML;

foreach ($comments as $comment) {
$output .= "\n
<li>"."<a href=\"" . get_permalink($comment->ID) .
"#comment-" . $comment->comment_ID . "\" title=\"on " .
$comment->post_title . "\">" .strip_tags($comment->comment_author)
.": " . strip_tags($comment->com_excerpt)
.": " .</a></li>

";
}

$output .= $post_HTML;

echo $output; ?>

Can anyone please help?