$comment_parent = isset($_POST['comment_parent']) ? absint($_POST['comment_parent']) : 0;
$commentdata = compact('comment_post_ID', 'comment_author', 'comment_author_email', 'comment_author_url', 'comment_content', 'comment_type', 'comment_parent', 'user_ID');
$comment_id = wp_new_comment( $commentdata );
$comment_parent = isset($_POST['comment_parent']) ? absint($_POST['comment_parent']) : 0;
$commentdata = compact('comment_post_ID', 'comment_author', 'comment_author_email', 'comment_author_url', 'comment_content', 'comment_type', 'comment_parent', 'user_ID');
$comment_id = wp_new_comment( $commentdata );