I don't know if you're still looking for the script, but I found something that you might be able to use
<script language="JavaScript">
<!-- Begin
var how_many_ads = 3;
var now = new Date()
var sec = now.getSeconds()
var ad = sec % how_many_ads;
ad +=1;
if (ad==1) {
url="http://LINK1";
alt="Alt Text";
banner="BUTTONURL1";
width="88";
height="31";
}
if (ad==2) {
url="http://LINK2";
alt="Alt Text";
banner="BUTTONURL2";
width="88";
height="31";
}
if (ad==3) {
url="http://LINK3";
alt="Alt Text";
banner="BUTTONURL3f";
width="88";
height="31";
}
document.write('<a href=\"' + url + '\" target=\"_blank\">');
document.write('<img src=\"' + banner + '\" width=')
document.write(width + ' height=' + height + ' ');
document.write('alt=\"' + alt + '\" border=0></a>');
// End -->
</script>
Here are the directions that came along with it:
At the very top you see it says "how_many_ads = 3" Change ONLY the number 3, because that is how many buttons you have on your button rotation, that is how many I have for this one, but if you have 20, more or less, then change it.
Then you will see "
http://LINK1" and "Alt Text" and also "BUTTONURL", you must change those 3 so they match up with each button your adding to the rotation
The buttons I am using on this tutorial are all 88x31, but you can use any size or type of button you like, just specify the size where you see "width='88" height="31"" with the size you want.
If you want to add more than 3 then just add this code, after the last one:
if (ad==3) {
url="http://LINK3";
alt="Alt Text";
banner="BUTTONURL3f";
width="88";
height="31"; }
(I assume you would need to change ad==3 to ad==4)