What I do
Best I can offer is the following which can be seen @
www.MississippiRollerGirls.com/home/html/MSRG/Home.html
Notice the sponsor window, hit refresh and a new sponsor pops up... I copied this code from I don't know where but it works for this; I'd like a truly random method myself; for instance if someone empties their cache every session, they will see the same image on next visit; I would like someway for it to be on 'shuffle'
code in snippet
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<html>
<head>
<title></title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
</head>
<body>
<noscript><img src="http://www.mississippirollergirls.com/home/html/MSRG/Sponsor_files/LiquidLounge.png"></noscript>
<script type="text/javascript">
function robin(){
//Set Your Images in the below Array:
var robin_im=['http://www.mississippirollergirls.com/home/html/MSRG/Sponsor_files/Moose_Lodge_WEB.jpg', 'http://www.mississippirollergirls.com/home/html/MSRG/Sponsor_files/HarleyD_WEB.png', 'http://www.mississippirollergirls.com/home/html/MSRG/Sponsor_files/LiquidLounge_WEB.png', 'http://www.mississippirollergirls.com/home/html/MSRG/Sponsor_files/Sonic_WEB.png', 'http://www.mississippirollergirls.com/home/html/MSRG/Sponsor_files/Venues_WEB.png','http://www.mississippirollergirls.com/home/html/MSRG/Sponsor_files/MOWA_WEB.jpg']
//set the links in the below Array:
var robin_link=['http://maps.google.com/maps?oe=utf-8&rls=org.mozilla:en-US

fficial&client=firefox-a&um=1&ie=UTF-8&q=5145+west+gay+d%27iberville,+ms&fb=1&split=1&gl=us&view=text&latlng=411836207323197233', 'http://www.coastharley.com', 'http://profile.myspace.com/index.cfm?fuseaction=user.viewprofile&friendID=125661409', 'http://www.google.com/search?client=safari&rls=en-us&q=sonic+ocean+springs,+ms&ie=UTF-8&oe=UTF-8', 'http://www.google.com/search?hl=en&client=safari&rls=en-us&q=venues+biloxi%2C+ms&btnG=Search','http://maps.google.com/maps?hl=en&client=firefox-a&ie=UTF8&q=mowa+development+gautier,+ms&fb=1&split=1&gl=us&view=map&ei=INj7Sdy6IovWM8eKpFw&cd=1']
//////////////// Stop Editing //////////////////
function createCookie(name,value,days) {
if (days) {
var date = new Date();
date.setTime(date.getTime()+(days*24*60*60*1000));
var expires = "; expires="+date.toGMTString();
}
else var expires = "";
document.cookie = name+"="+value+expires+"; path=/";
}
function readCookie(name) {
var nameEQ = name + "=";
var ca = document.cookie.split(';');
for(var i=0;i < ca.length;i++) {
var c = ca
;
while (c.charAt(0)==' ') c = c.substring(1,c.length);
if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
}
return null;
}
function eraseCookie(name) {
createCookie(name,"",-1);
}
var num=readCookie('robim')? readCookie('robim')*1 : 0;
document.write('<a href="'+robin_link[num]+'"><img src="'+robin_im[num]+'"></a>')
num=num<robin_im.length-1? num+1 : 0;
createCookie('robim', num);
}
robin();
</script>
</body>
</html>
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end of snippet
good luck