how can i use data from custom config in custom helper file

[eluser]DanTyan[/eluser]
Hello

i need to use data from custom config in my helper file, is anybody know how i can do it?

now my code looks like this:

Code:

$this->config->load('compass');
$this->load->helper('design');

and in helper i need

Code:

function image($sImageName)
{
    return base_url() . $this->config->item('images', 'design') . $sImageName;
}

any ideas?