How to add dynamic CSS and JS - need help

Hi, I'm new to CodeIgniter.

I've been trying to use this code http://dondanu.com/add-dynamic-css-and-j...deigniter/
(another article i've found was 2013 http://jamshidhashimi.com/2013/04/12/dyn...ader-page/ )

It says:

1. Add new config item in your config file:

PHP Code:

$config['css_path'] = 'assets/css/'; 


2. Create new helper file “helper/queuescript_helper.php”
3. In your controller file use below code,

PHP Code:

$data['css'] = array('bootstrap.css','custom.css');

$data['js'] = array('bootstrap.js','custom.js'); 


4. In your view,

PHP Code:

<?php queue_css($css);?>

<?php queue_js($js);?>

***

I ended up with this code (after rewriting it a bit):

PHP Code:

<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');

if ( ! function_exists('css_url'))
{
 function css_url()
 {
 $CI =& get_instance();
 return base_url() . $CI->config->item('css_path');
 }
}

/**
 * Load CSS
 * Creates the <link> tag that links all requested css file
 * @access  public
 * @param   string
 * @return  string
 */
if ( ! function_exists('queue_css'))
{
    function queue_css($file, $media='all')
    {
        if(!empty($file)){
            foreach($file as $e) {
                $element = '<link rel="stylesheet" href="' . css_url() . $e . '"';

                foreach ( $atts as $key => $val )
                    $element .= ' ' . $key . '="' . $val . '"';
                $element .= ' />'."\n";
                echo $element;
            }
        }
    }
}

/**
 * Load JS
 * Creates the <script> tag that links all requested js file
 * @access  public
 * @param   string
 * @param     array     $atts Optional, additional key/value attributes to include in the SCRIPT tag
 * @return  string
 */

if ( ! function_exists('js_url'))
{
 function js_url()
 {
 $CI =& get_instance();
 return base_url() . $CI->config->item('js_path');
 }
}


if ( ! function_exists('queue_js'))
{
    function queue_js($file, $atts = array())
    {
        if(!empty($file)){
            $element = '<script type="text/javascript" src="' . js_url() . $file . '"';

            foreach ( $atts as $key => $val )
                $element .= ' ' . $key . '="' . $val . '"';
            $element .= '></script>'."\n";

            echo $element;
        }
    }
}
/* End of file queuescript_helper.php */ 


I added queuescript into autoload:

PHP Code:

$autoload['helper'] = array('html', 'url', 'queuescript'); 


There was an error:

"Undefined variable: atts" and "Invalid argument supplied for foreach()"
line 27, that is:

PHP Code:

foreach ( $atts as $key => $val ) 


But I added $atts = array() into line 21

PHP Code:

queue_css($file, $media='all',$atts = array()) 


My base url is http://localhost/public_html

path to css folder is: public_html/styles

js folder is next to the codeigniter application folder

in config I've got (I tried all variants of path):

PHP Code:

$config['css_path'] = 'styles/';
$config['js_path'] = '../js/'; 


My browser doesn't see nor js nor css files. (I've restarted my wamp server).
Please, help!