Code:
<html>
<head>
<!--
This file retrieved from the JS-Examples archives
http://www.js-examples.com
1000s of free ready to use scripts, tutorials, forums.
Author: Artem - http://javascript4free.by.ru
-->
</head>
<body>
<script LANGUAGE="JavaScript">
// !!! Reload page
// add 1,2,3 'img'
var NumberOfAds = 4;
var now = new Date()
var sec = now.getSeconds()
var AdNumber = sec % NumberOfAds;
AdNumber +=1;
if (AdNumber==1)
{
url="http://www.developerbarn.com/";
Graphic="/js/images/pic1.gif";
width = "220"
height = "40"
}
if (AdNumber==2)
{
url="http://www.developerbarn.com/";
Graphic="/js/images/pic2.gif";
width = "220"
height = "40"
}
if (AdNumber==3)
{
url="http://www.developerbarn.com/";
Graphic="/js/images/pic3.gif";
width = "268"
height = "50"
}
if (AdNumber==4)
{
url="http://www.developerbarn.com/";
Graphic="/js/images/pic4.gif";
width = "220"
height = "40"
}
document.write('<center>');
document.write('<a href=\"' + url + '\">');
document.write('<img src=\"' + Graphic + '\" width=')
document.write(width + ' height=' + height + ' ');
document.write('border=0><br>');
document.write('</a>');
document.write('</center>');
</script>
<br>
<center>REST OF HTML DOCUMENT HERE
<br><b><font color=red>Type reload some times, You will see change</font><BR><center><a href='http://www.developerbarn.com'>JS-Examples.com</a></center>
</body>
</html>