Är det så här du menar?
<html>
<head>
<script language="JavaScript">
function RandomNumber() {
today = new Date();
num= Math.abs(Math.sin(today.getTime()));
return num;
}
</script>
</head>
<body>
<script language="JavaScript">
<!--
document.write("This is a random number:", RandomNumber());
// -->
</script>
</body>
</html>
/Pele