problemer med paging script

Jeg har hentet et script som jeg ikk kan få til at fungere så vil hører om der er nogen der kan hjælpe. i kan se hvad den gør her.. www.play4all.dk/paging.php

dette er scriptet

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<?
//REMEMBER TO CONNECT TO DATABASE!
include("includes/dbconnect.php");
//**EDIT TO YOUR TABLE NAME, ECT.

$t = mysql_query("SELECT * FROM channels");
  if(!$t) die(mysql_error());
   
$a                = mysql_fetch_object($t);
$total_items      = mysql_num_rows($t);
$limit            = $_GET['limit'];
$type            = $_GET['type'];
$page            = $_GET['page'];

//set default if: $limit is empty, non numerical, less than 10, greater than 50
if((!$limit)  || (is_numeric($limit) == false) || ($limit < 10) || ($limit > 50)) {
    $limit = 10; //default
}
//set default if: $page is empty, non numerical, less than zero, greater than total available
if((!$page) || (is_numeric($page) == false) || ($page < 0) || ($page > $total_items)) {
      $page = 1; //default
}

//calcuate total pages
$total_pages    = ceil($total_items / $limit);
$set_limit          = $page * $limit - ($limit);

//query: **EDIT TO YOUR TABLE NAME, ECT.

$q = mysql_query("SELECT * FROM channels LIMIT $set_limit, $limit");
  if(!$q) die(mysql_error());
    $err = mysql_num_rows($q);
      if($err == 0) die("No matches met your criteria.");

//Results per page: **EDIT LINK PATH**
echo(" 
<a href=http://www.play4all.dk.php?cat=$cat&amp;limit=10&amp;page=1>10</a> |
<a href=http://www.play4all.dk.php?cat=$cat&amp;limit=25&amp;page=1>25</a> |
<a href=http://www.play4all.dk.php?cat=$cat&amp;limit=50&amp;page=1>50</a>");

//show data matching query:
while($code = mysql_fetch_object($q)) {
    echo("item: ".$code->title."<BR>");
}

$cat = urlencode($cat); //makes browser friendly

//prev. page: **EDIT LINK PATH**

$prev_page = $page - 1;

if($prev_page >= 1) {
  echo("<b>&lt;&lt;</b> <a href=http://www.play4all.dk.php?cat=$cat&amp;limit=$limit&amp;page=$prev_page><b>Prev.</b></a>");
}

//Display middle pages: **EDIT LINK PATH**

for($a = 1; $a <= $total_pages; $a++)
{
  if($a == $page) {
      echo("<b> $a</b> | "); //no link
    } else {
  echo("  <a href=http://www.play4all.dk.php?cat=$cat&amp;limit=$limit&amp;page=$a> $a </a> | ");
    }
}

//next page: **EDIT THIS LINK PATH**

$next_page = $page + 1;
if($next_page <= $total_pages) {
  echo("<a href=http://www.play4all.dk.php?cat=$cat&amp;limit=$limit&amp;page=$next_page><b>Next</b></a> &gt; &gt;");
}

//all done
?>