Duplicate code optimized using a function - php

Question

I have a bunch of code that I am using for pagination. I use this string of code at the top of a very long page, and I also have the exact same code at the bottom of the page. Duplicating the code doesn't seem very efficient. I am looking to optimize my page by somehow having the code called once at the top of the page, and then have something that just places that same code at the bottom of the page....
I think this can be done with functions, but my php isn't very good and the few tries I've done have resulted in failure. There are alot of variables that go into the function ($total_num_results, $perpage, $p, $pages) and I think that is where I get lost ... Can someone show me how to do this using a function?
Alternatively, I though that I could create an include (and just call the file twice), but I would like to avoid linking to other files...
<center>
Page: <span class="pagination"><?php
// PREVIOUS link
if($total_num_results > $perpage && $p!='1')
{
$p1 = $p-1;
echo "previous";
} else {
echo '<span class="paginationon">previous</span>';
}
// Pages
for ($i=0; $i < $pages; $i++)
{
$j = $i+1;
if ($j == $p)
{
echo '<span class="paginationon">'.$j.'</span>';
} else {
echo ''.$j.'';
}
}
// NEXT link
if($total_num_results > $perpage && $p!=$pages)
{
$p2 = $p+1;
echo 'next';
} else {
echo '<span class="paginationon">next</span>';
}
?></span>
</center>

Answer 1

<?php
function pagination(){
global $total_num_results, $perpage, $p, $pages;
if($total_num_results > $perpage && $p!='1')
{
$p1 = $p-1;
echo "previous";
} else {
echo '<span class="paginationon">previous</span>';
}
// Pages
for ($i=0; $i < $pages; $i++)
{
$j = $i+1;
if ($j == $p)
{
echo '<span class="paginationon">'.$j.'</span>';
} else {
echo ''.$j.'';
}
}
// NEXT link
if($total_num_results > $perpage && $p!=$pages)
{
$p2 = $p+1;
echo 'next';
} else {
echo '<span class="paginationon">next</span>';
}
}
?>
Then in the HTML
<center>
Page: <span class="pagination"><?php pagination(); ?></span>
</center>