modifying the PHP script from Demo4

I'm currently modifying the PHP script from the demo4.
In that demo you must specifie your poll_id manualy.

I want that the computer automaticly selects the newest poll_id.
How can I do that? I used the help and it shows this anwser

<?php
include_once "/var/www/html/wannahave-it/htdocs/poll/db/booth.php";
echo $php_poll->poll_process("newest");
?>

But this is for a complete poll, I just want a tag that selects the latest poll _id so the returned value can be just "8".

Anyone?

This is about Advanced poll 2.0.2.

<?php
include_once "/var/www/html/wannahave-it/htdocs/poll/db/booth.php";
$my_id = $php_poll->get_latest_poll_id();

echo $my_id;
?>

thanks!