Reusable Custom WordPress Meta Boxes

Hi all,

I am having a some trouble getting this code to work:-

I have installed it as instructed. I copied the custommetabox folder to my theme and used this to load the scrips:-

wp_enqueue_style('custommeta', get_template_directory_uri().'/metaboxes/meta_box.php');

In my themes functions file I added the following from the examples provided:-

$prefix = 'sample_';

$fields = array(
	array( // Text Input
		'label'	=> 'Text Input', // <label>
		'desc'	=> 'A description for the field.', // description
		'id'	=> $prefix.'text', // field id and name
		'type'	=> 'text' // type of field
	),
	array( // Textarea
		'label'	=> 'Textarea', // <label>
		'desc'	=> 'A description for the field.', // description
		'id'	=> $prefix.'textarea', // field id and name
		'type'	=> 'textarea' // type of field
	)
);

Then I loaded the metaboxes the same way as my custom posts:-

function add_custom_meta()
{
add_meta_box( 'sample_box', 'Sample Box', $fields, 'page', true );
}
add_action('add_meta_boxes', 'add_custom_meta');

I get the following errors in the admin area:-
SCREAM: Error suppression ignored for
Warning: call_user_func() expects parameter 1 to be a valid callback, no array or string given in C:\wamp\www\psytech\wp-admin\includes\template.php on line 927

Any ideas?