PHP pagination class

[PHP]
class pagination
{
 public function __construct()
 {
 }
 public function calculate_pages(&$total_rows, $rows_per_page, &$page_num)
 {
  $arr = array();
  // calculate last page
  $last_page = ceil($total_rows / $rows_per_page);
  // make sure we are within limits
  $page_num = (int) $page_num;
  if ($page_num < 1)
  {
     $page_num = 1;
  } 
  elseif ($page_num > $last_page)
  {
     $page_num = $last_page;
  }
  $upto = ($page_num - 1) * $rows_per_page;
  $arr['limit'] = 'LIMIT '.$upto.',' .$rows_per_page;
  $arr['current'] = $page_num;
  if ($page_num == 1)
   $arr['previous'] = $page_num;
  else
   $arr['previous'] = $page_num - 1;
  if ($page_num == $last_page)
   $arr['next'] = $last_page;
  else
   $arr['next'] = $page_num + 1;
  $arr['last'] = $last_page;
  $arr['info'] = 'Page ('.$page_num.' of '.$last_page.')';
  $arr['pages'] = $this->get_surrounding_pages($page_num, $last_page, $arr['next']);
  return $arr;
 }
 function get_surrounding_pages($page_num, $last_page, $next)
 {
  $arr = array();
  $show = 5; // how many boxes
  // at first
  if ($page_num == 1)
  {
   // case of 1 page only
   if ($next == $page_num) return array(1);
   for ($i = 0; $i < $show; $i++)
   {
    if ($i == $last_page) break;
    array_push($arr, $i + 1);
   }
   return $arr;
  }
  // at last
  if ($page_num == $last_page)
  {
   $start = $last_page - $show;
   if ($start < 1) $start = 0;
   for ($i = $start; $i < $last_page; $i++)
   {
    array_push($arr, $i + 1);
   }
   return $arr;
  }
  // at middle
  $start = $page_num - $show;
  if ($start < 1) $start = 0;
  for ($i = $start; $i < $page_num; $i++)
  {
   array_push($arr, $i + 1);
  }
  for ($i = ($page_num + 1); $i < ($page_num + $show); $i++)
  {
   if ($i == ($last_page + 1)) break;
   array_push($arr, $i);
  }
  return $arr;
 }
}
[/PHP]

call

$p = new pagination();

$arr = $p->calculate_pages(70, 10, 1);