image change on refresh : what is the code for this page

[nivar]

hey guys, i came across the this page, it has some cool feuture, what it is
it changes image on every refresh..
anyone know what is the php code to do this?  i want to implement sowhat
same page in my front page of the gallery.

here the link to the page:
http://www.candidcn.com/magic/magic.php

thanks in advance.

[Joachim Müller]

This is not related to coppermine.