wordpress slug checker

function disallow_posts_with_same_name($messages) {
    global $post;
    global $wpdb;
    $name = $post->post_name;
    $post_id = $post->ID;
    $wtquery_post = "SELECT post_name FROM $wpdb->posts WHERE post_status = 'publish' AND post_type = 'post' AND post_name = '{$name}' AND ID != {$post_id}";
    $wtquery_page = "SELECT post_name FROM $wpdb->posts WHERE post_status = 'publish' AND post_type = 'page' AND post_name = '{$name}' AND ID != {$post_id}";

    $wresults_post = $wpdb->get_results($wtquery_post);
    $wresults_page = $wpdb->get_results($wtquery_page);

    if ( $wresults_post || $wresults_page ) {
        $error_message = 'Bezpośredni odnośnik o tej samej nazwie już istnieje. Zmień go aby uniknąć problemów z duplikowaniem się adresów.';
        add_settings_error('post_has_links', '', $error_message, 'error');
        settings_errors( 'post_has_links' );
        $post->post_status = 'draft';
        wp_update_post($post);
        return;
    }
    return $messages;

}
add_action('post_updated_messages', 'disallow_posts_with_same_name');

function disallow_posts_with_same_name_js() {
    echo '"<script>
            (function($) {
                $(document).ready(function(){
                    if ( $( "#setting-error-sname" ).length ) {
                        $( "#setting-error-sname, #editable-post-name" ).animate({backgroundColor:"#dc3232",color:"#fff",padding:"2px 4px"},\'slow\');
                    }
                });
            })( jQuery );
           </script>"';
}
add_action('admin_footer', 'disallow_posts_with_same_name_js');