Sono sempre io...
Per comodità copio il codice html, css e js(non utile allo scopo finale) della mia pagina...stanotte ero cotto e nn l'ho postato!

HTML

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html lang="en" xml:lang="en" xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Personal Webpage</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<link href="cssmodello.css" rel="stylesheet" type="text/css" media="screen" />
<script src="fixedbackground.js" type="text/javascript"></script>
</head>

<body onload="fixedBackground('imagini%20per%20home/logo3.gif';)
<div id="container">
<div id="header">
<h1 class="titolo">Nome della mia homepahe |</h1>
<h2 class="titolo1">Personal
Website</h2>
</div>
<div id="nav">
<ul id="menu">
[*][*][*][/list]
</div>
<div id="main">
</div>
<div id="footer">
</div>

</div>
</body>
</html>

CSS

@charset "utf-8";
/* CSS Document */
* {
margin:0;
padding:0;
}
html, body {
height:100%;
}
html {
background-image:url(imagini%20per%20home/sfondo.gif);
background-repeat:repeat-x;
background-size:contain;
background-attachment:scroll;
}
body {
background-image:url(imagini%20per%20home/logo3.gif);
background-size:cover;
background-attachment:scroll;
font-family:Verdana, Geneva, sans-serif;
font-size:76%;
}
#container {
height:100%;
}
#header {
height: 8em;

}
.titolo {
font-size:5em;
line-height: 1em;
}
.titolo1 {
font-size:2.6em;
}


JS trovato in internet. Forse puo tornar utile a qlk ma non al mio scopo,quindi, si potrebbe evitare di leggerlo.


//--------------------------------------------------------------//
// Full Window (stretched) Watermarked Background Image v2.0.1. //
//--------------------------------------------------------------//
// //
// Copyright (C) 2002-2004 QCS Systems Inc. //
// //
// This JavaScript can be used with permission as long as //
// this message stays here in the header of the script. Any //
// modifications and bug fixes are appreciated. //
// //
// Author : D.J.Oepkes //
// Date : 11/22/2002 //
// Email : joepkes@qcssystems.com //
// //
//--------------------------------------------------------------//
// Modifications //
//--------------------------------------------------------------//
// 11/22/2004 D.J.Oepkes, Total rebuild as I finally found an //
// excellent way to do away with java- //
// script to position it. It's now all //
// done through CSS and an easy onload //
// function does all the layering work //
//--------------------------------------------------------------//
// 01/12/2005 D.J.Oepkes, Removed one layer out the equation. //
// Also removed layer-position: fixed //
// to make flash work in firefox. //
//--------------------------------------------------------------//

var backgroundset=false; // do not change, for internal use only

//--------------------------------------------------------------//
// fixedBackground //
//--------------------------------------------------------------//
// set the fixed background image. If Called for the first time //
// it will set the necessary body styles, layers, and images to //
// create the fixed background effect, otherwise it will just //
// change the background image. //
// //
// Insert the following into the html to load the script //
// <script src="fixedbackground.js"></script> //
// //
// 1) How to Use in body-tag (preferred): //
// <body onload="fixedBackground('background.jpg');"> //
// //
// 2) How to Use in link: //
// <a href="javascript:fixedBackground('background.jpg') ;"> //
// Try this background... //
// </a> //
// //
// 3) How to use in script: //
// <script> //
// fixedBackground('background.jpg'); //
// </script> //
//--------------------------------------------------------------//

function fixedBackground(url)
{
if(!backgroundset)
{
document.body.style.overflow = 'hidden';
document.body.style.padding = '0px';
document.body.style.margin = '0px';

var overlay = document.createElement('DIV');
overlay.style.position = 'absolute';
overlay.style.top = '0px';
overlay.style.left = '0px';
overlay.style.height = '100%';
overlay.style.width = '100%';
overlay.style.overflow = 'auto';

overlay.innerHTML = document.body.innerHTML;
document.body.innerHTML = '[img]' + url + '[/img]';

document.body.appendChild(overlay);

backgroundset=true;
}
else
background.src=url;
}

//--------------------------------------------------------------//
//--- Prelevato ed illustrato su http://www.web-link.it -----//