dynamic base url
// open folder Application -> config -> config.php
// change $config['base_url'] = ''; to this code
$root=(isset($_SERVER['HTTPS']) ? "https://" : "http://").$_SERVER['HTTP_HOST'];
$root.= str_replace(basename($_SERVER['SCRIPT_NAME']), '', $_SERVER['SCRIPT_NAME']);
$config['base_url'] = $root;