where do I get a complete information/tutorial about pagination class?

[eluser]Reynolds[/eluser]
I have url

http://localhost/myshop/index.php/shop/category/1/1/

controller class: shop
method: category
parameters: category_id,class_id

if I click on 2 it will generate...
http://localhost/myshop/index.php/shop/category/1/1/2

but the created pagelinks always shows

Code:

1 2 3 >  Last ›

if I click on 3 it generate

http://localhost/myshop/index.php/shop/category/1/1/4


am I doing something wrong?

the config i

Code:

$config['base_url'] = PARENT_PATH . "shop/category/{$res_category->category_id}/" . $class_id . "/";
$config['total_rows'] = $qry_product->num_rows();
$config['per_page'] = '2';

thanks in advance

[eluser]Reynolds[/eluser]
ok solved..

Code:

$config['uri_segment'] = '5';

I had to study Pagination class to get the idea.