Random picture every time it's accessed

[Skootles]

Well I'm sure everyone's seen this at one time or another. It's when someone has an image displaying on a page, and every time you refresh it, a different picture appears. Now, I'm talking about the actual image changing, but the name remaining the same.

For example, you load the page, and the image shows up. The image's location is "http://www.whatever.com/image.jpg". Now, you refresh the page, and the image is different, but it's still located at "http://www.whatever.com/image.jpg".

So hopefully that makes sense... and I'm wondering how would I do this? Does anyone know of a tutorial anywhere? I tried google, but didn't find what I was looking for.

If you need more clarification, just reply and I'll try to explain as best I can.

[visualAd]

Do you mean like the picture in my signature? Here's the script I use, it's written in PHP:

<?php
    $dir = opendir('.');
    $file_array = array();

    while(($file = readdir($dir)) !== false) {
        /* create an array of all jpeg imagesi n the current directory */       
        if (strtolower(substr($file, -3)) == 'jpg') {
            $file_array[] = $file;
        }
    }

    /* send headers to prevent the browser from caching the image */

    // Date in the past
    header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");

    // always modified
    header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
 
    // HTTP/1.1
    header("Cache-Control: no-store, no-cache, must-revalidate");
    header("Cache-Control: post-check=0, pre-check=0", false);

    // HTTP/1.0
    header("Pragma: no-cache");

    header('Content-Type: image/jpeg');

    srand((float) microtime() * 10000000);
    $file = array_rand($file_array);

    /* display a random picture */
    readfile($file_array[$file]);
?>

[Skootles]

Yep, just like that.
So would I have to put that php code into my sig? [I'm doing it for a forum too :P]

EDIT: Actually, I think I'd just have to host that and then put the link to the page as the image... I'll try it out

EDIT 2: Yep, worked perfectly. Thanks alot