Always show next page link in pager function mythemename_pager_next($text, $limit, $element = 0, $interval = 1, $parameters = array()) {
  global $pager_page_array, $pager_total;
  $output = '';

  // If we are anywhere but the last page
  if ($pager_page_array[$element] &lt; ($pager_total[$element] - 1)) {
    $page_new = pager_load_array($pager_page_array[$element] + $interval, $element, $pager_page_array);
    // If the next page is the last page, mark the link as such.
    if ($page_new[$element] == ($pager_total[$element] - 1)) {
      $output = theme('pager_last', $text, $limit, $element, $parameters);
    // The next page is not the last page.
    } else {
      $output = theme('pager_link', $text, $page_new, $element, $parameters);
      //$output = '&lt;li class="custom-pager-next"&gt;&lt;a class="active" href="javascript: void(0)"&gt;&lt;img width="10" height="19" title="" alt="Previous" src="/' . path_to_theme() . '/img/pager-previous.png"&gt;&lt;/a&gt;&lt;/li&gt;';
    }
  }

  return $output;


}

How to make NEXT PAGE link visible on last page? For example we have 3 pages and i am on the 3rd page and i should see NEXT page link. Please assist to me with function above, thanks!
The line

if ($page_new[$element] == ($pager_total[$element] - 1)) {


Will never fire because of the earlier line: 

if ($pager_page_array[$element] &lt; ($pager_total[$element] - 1)) {


So if the current page is equal to (or higher) then the last page it will skip the whole code. 

Try removing that line (and the corresponding closing bracket }).
I hovever don't know if it will keep working then because the following function seems to be assuming it can never load a pager higher then the current page. So prepare for some unexpected behavior.

$page_new = pager_load_array($pager_page_array[$element] + $interval, $element, $pager_page_array);