http://www.phpinsider.com/php/code/Smarty/

The idea behind a templating system is to separate logic from layout. The Smarty Template system does a good job of doing this. Here we will convert our basic guestbook example to use Smarty. 

% ls -R
.:
config/      smartyguest.php       templates/      templates_c/

./templates:
smartyguest.tpl

./templates_c:
smartyguest.tpl.php
We separate the HTML from the PHP code into templates/smartyguest.tpl and ./smartyguest.php respectively.

templates/smartyguest.tpl
<html><head><title>My Guestbook</title></head>
<body>
<h1>Welcome to my Guestbook</h1>
<h2>Please write me a little note below</h2>
<form action="{$SCRIPT_NAME}" method="POST">
<textarea cols=40 rows=5 name="note" wrap=virtual></textarea>
<input type="submit" value=" Send it ">
</form>
<h2>The entries so far:</h2>
{section name=msgs loop=$notes}
  {$notes[msgs].id} {$notes[msgs].ts} {$notes[msgs].comment}<br>
{/section}
</body></html>
smartyguest.php
<?php
require('Smarty.class.php');

$smarty = new Smarty;
$smarty->debugging = true;

mysql_connect('localhost','nobody');
mysql_select_db('mydb');

/* insert new note */
if(isset($note)) {
    $ts = date("Y-m-d H:i:s");
    mysql_query("insert into comments values 
                 (0,'$note','$ts')");
}

/* read existing notes */
$result = mysql_query('select * from comments');
if(!$result) echo mysql_error();
while($notes[]=mysql_fetch_array($result,MYSQL_ASSOC));
$smarty->assign('notes',$notes);

$smarty->display("smartyguest.tpl");
?>