The example above is accomplished with the following JavaScript code. This code makes the browser to randomly insert one of 3 pictures at the location where the code is placed. You can put this code to anywhere on a webpage. Just make sure that the paths to the pictures are adjusted correctly.
 
    

<script language="javascript"><!-- //array with possible pictures var pictures = new Array( "picture1.jpg", "picture2.jpg", "picture3.jpg" ); //write img-tag with random src-attribute to page var rnd = Math.floor(Math.random() * pictures.length); document.write('<img src="' + pictures[rnd] + '">'); //--></script>