script LANGUAGE="JavaScript">
<!-- This script and many more are available free online at -->
<!-- The JavaScript Source!! http://javascript.internet.com -->
<!-- Begin
var maxAdNo = 2
var adNo
var myAd = new Array()
myAd[0] = 'PUT CODE FOR IMAGE 1 HERE - Include <img...> tag and link (<a....>)'
myAd[1] = 'IMAGE 2'
myAd[2] = 'IMAGE 3'
// End -->
</script>
Place this in the BODY of the page - basically wherever you want the banners to appear.
CODE
<script LANGUAGE="JavaScript">
<!-- Begin
adNo = Math.round(Math.random() * maxAdNo)
document.write(myAd[adNo])
// End -->
</script>