I have problem with set cookie in codeigniter

[eluser]Unknown[/eluser]
Hello everybody!

I want to set cookie on page load, i put this code in index.php

Code:

if (!isset($_COOKIE['LANG'])){
setcookie('LANG', 'en', time()+86500,'/','');

}

When i enter website on the address bar in browsers as Chrome, IE... Cookie is not set up, i have to refresh website, cookie has done well. I want to set cookie on page load without refreshing my website, what can i do? Thanks for your help.