Add link for next page and back page - seperate to paging

[propertysnaps]

Hello,
Is it possible to add a button (image) to my categories.html page that will make it go to the next page?

I already have the paging setup like this   << 1,2,3,4 >> last page

But I want to add some extra buttons on another part of the screen,

I want one of those buttons to take me to the next page  (so it will go to:    /categories.php?cat_id=7&page=2)  where the 2 is the next page

Does any one know what code I can add to the link to make it dyanmically go to the next page? 

I would have thought that categories.php?cat_id=7&page=$next_page  would work - but it doesnt.

[V@no]

In categories.php find:
  "paging" => $getpaging->get_paging(),

Insert _below:
  "page_next" => ($page <= $getpaging->total_pages) ? $link_arg . "&amp;page=" . ($page + 1) : "",
  "page_prev" => ($page > 1) ? $link_arg . (($page > 2) ? "&amp;page=" . ($page - 1) : "") : "",


In template use {page_next} and {page_prev} tags