Calling 'require_once' from a controller

[eluser]thekrow[/eluser]
Hello,

I'd like to know why I'm getting an error when I call "load_file()" located in my index function in my one of my controllers, something like this:

function index()
{
$this->load_files();
}

function load_files()
{
require_once('top_file.php');

$this->smarty->assign('top',$top);
}

The error I'm getting is "Undefined variable: top". The 'top' variable as you can see from the code is stored in "top_file.php". I don't understand why the variable is undefined. If I call "require_once()" directly in index() then my program works fine. The problem is when I use require_once in a different function different from index().

Any help/suggestions will mean a lot to me, thank you.