Cambio immagine random

[ocir]

Ho provato così ma non carica cioè mi compare l'icona spezzata
Dove sbaglio?

<div><script type="text/javascript">// <=!=[=C=D=A=T=A=[
//--><=!=[=C=D=A=T=A=[//><!--
var images = new Array()
function preload() {
for (i = 0; i < preload.arguments.length; i++) {
images[i] = new Image()
images[i].src = preload.arguments[i]
}
}
preload(
"http://www.................../1.jpg",
"http://www.................../2.jpg",
"http://www.................../3.jpg",
"http://www.................../4.jpg"
)
//--><!
// ]=]=></script></div>
<script type="text/javascript" language="JavaScript">// <=!=[=C=D=A=T=A=[
img = new Array()
ran = Math.floor(4 * Math.random());
img[0] = 'www.................../1.jpg';
img[1] = 'www.................../2.jpg';
img[2] = 'www.................../3.jpg';
img[3] = 'www.................../4.jpg';
document.write("<img src=\""+img[ran]+"\">");
// ]=]=></script>