<html>
<head>
<script type="text/javascript" src="https://stackoverflow.com/questions/1554396/jquery.js"></script>
<script>
$(document).ready(function(){
var locations = ["http://webPage1.com", "http://webPage2.com"];
var len = locations.length;
var iframe = $('#frame');
var i = 0;
setInterval(function () {
iframe.attr('src', locations[++i % len]);
}, 30000);
});
</script>
</head>
<body>
<iframe id="frame"></iframe>
</body>
</html>