<img id="image1" name="image1" src="images/p04.jpg" />
<script language="javascript">
setInterval("RandomImage();",1000);
function RandomImage()
{
var num = Math.random()*3;
num = Math.round(num);
num = num + 1;
document.image1.src="images/p0" + num + ".jpg";
}
</script>