So the first thing we need to do, is to start PHP, get our class file and start the class.

<?php
	require_once('page.php');
	$tut = new tutorials;

Our class is being stored in the variable, $tut. Now we need to check to see if ID is set, if not, then we show an error.

<?php	//If ID isn't set show error
	if( !isset( (int)$_GET['id'] ) ){
		print 'No ID is set.';
	}else{

If is not set, ID (must be integer), then show error, else, we get ID into a variable.

<?php		//Get the ID of the tutorial
		$id = (int)$_GET['id'];

We now refer back to our class and get the tutorial requested.

<?php		$sql = $tut->get_tut($id);
		$r = mysql_fetch_array($sql);

Now I'm not going to explain this next bit, since it's already explained in the comments.

<?php		//Split up the tutorial
		//Explode splits a string on a string sperator and returns an array of components
		//In this sense, we split it up where [ nextpage ] is present.
		//You will need to take out the spaces between [ n and e ] below.
		$content = explode('[ nextpage ]', $r['content']);

Now we count the number of components in the array, so we can get the number of pages.

<?php		//We now count the number of components in the array.
		$num = count( $content );

This next bit checks to see if a page is set or not.

<?php		//If no page is set.
		if( !isset( $_GET['page'] ) ){

If it isn't, then we need to make page as 1.

<?php			//Then set page as 1
			$page = 1;

Otherwise it is set, so we can make it into a variable while still making sure it's an integer.

<?php		}else{
		
			//Otherwise page is what is set
			$page = (int)$_GET['page'];
		}

Now that we got everything, let's show the tutorial information.

<?php		print '<div class="top">
			<div class="title">'. $r['title'] .'</div>
			<div class="info">Posted on '. $r['postdate'] .' by '. $r['username'] .'</div>
			<div class="pages"><strong>Total Pages:</strong> '. $num .'</div>
		</div>';

That's just how I've done mine in the example, you can change it to your liking. This next bit of code refers back to the pagination, and actually shows our pages (if there is more than one page, remember?)

<?php		$tut->pagination($num, $page, $id);

So we send the number of pages, the page we're on, and the ID of the tutorial. Now we can show the actual tutorial.

<?php		print $content[$page - 1];

Remember that arrays start with 0, so page 1 in the array is actually 0, so we take 1 away (Well it wouldn't look good saying Page 0 would it?). Almost done, three more lines to do, first one, we show the pagination again, so now we have the pagination above and below the tutorial, then we end the else statement (if ID is set), and end php.

<?php		$tut->pagination($num, $page, $id);
	}
?>

Well that's it, that's a fairly advanced pagination on a single field in a query.