Hola, ya llegué.
Código PHP:
<html>
<head>
<title>Untitled Document</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<script language="JavaScript" type="text/JavaScript">
// ***********************************************
// ***********************************************
// Author : biblio
// Date : 25/07/03
// ***********************************************
function image() {};
image = new image();
number = 0;
// Generamos un array
image[number++] = "<img src='1.jpg' border='0'>"
image[number++] = "<img src='2.jpg' border='0'>"
image[number++] = "<img src='3.jpg' border='0'>"
image[number++] = "<img src='4.jpg' border='0'>"
image[number++] = "<img src='5.jpg' border='0'>"
// Generamos un numero en forma aleatoria
increment = Math.floor(Math.random() * number);
</script>
</head>
<body>
<div id="Layer1" style="position:absolute; width:278px; height:103px; z-index:1; left: 278px; top: 115px;">
<script language="JavaScript" type="text/JavaScript">
document.write(image[increment]); // finalmente visualizamos la imagen
</script>
</div>
</body>
</html>
Ahi está tu pedido.
Saludos