how to pass data array into layout at Phil’s template library?

[eluser]Unknown[/eluser]
please advice.

how to pass data array into layout at Phil’s template library?
so far, i just can view the data successfully at the view only, not in layout.
i.e. $this->template->build('home', $data);

but it will get error if we do at layout:
$this->template->set_layout('main', $data);

regards,

hadi