using PHP it would be easy.
Code:
<?php
$banner = rand(1,10);
echo "<img src='.../images/banners/banner$banner.jpg/'>";
?>
something like that would give you a random banner... you will need to edit it based on your situation. If you give me how many you have and the directory they are in, I can change it to your needs. If you want a visual interface to adding banners I can code that for you for about $10. Please let me know. MSN preferably.
Sincerely,
Jordan Martin
Seraskier