Ciao a tutti ho un problema...

se creo una pagina con questo codice:


codice:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>
<script type="text/javascript">
function ChangeCSSBgImg() {
    debugger;
    if (!document.getElementById) return false;
    var MyElement = "MyBody";
    var ImgPath = "Img/";
    var HomePage = "default.aspx";
    if (!document.getElementById(MyElement)) return false;

    var random_images = new Array();
    random_images[0] = "01.gif";
    random_images[1] = "02.gif";
    random_images[2] = "03.gif";
    random_images[3] = "04.gif";
    var $header = document.getElementById(MyElement);
    var $backgroundurl = $header.style.backgroundImage;
    var sPath = window.location.pathname;
    var sPage = sPath.substring(sPath.lastIndexOf('/') + 1);
    var ImgURL = "";
    if (sPage.toLowerCase() == HomePage || sPage == "") {
        ImgURL = "none"
    } else {
        ImgURL = "url(" + ImgPath + random_images[rand(random_images.length)] + ")"; 
    }
    if ($backgroundurl != ImgURL) {
        $header.style.backgroundImage = ImgURL;
    }
    movement = setTimeout("ChangeCSSBgImg()", 14000);
}
function rand(n) {
    return (Math.floor(Math.random() * n));
}
function addLoadEvent(func) {
    var oldonload = window.onload;
    if (typeof window.onload != 'function') {
        window.onload = func;
    } else {
        window.onload = function() {
            oldonload();
            func();
        }
    }
}
addLoadEvent(ChangeCSSBgImg);
    </script>
</head>

<body id="MyBody">
</body>
</html>
lo script contenuto funziona correttamente...

ma messo sul sito dove mi serve no...

qualcuno mi aiuta a capire perchè?

questo e' il sito

ps:lo script fà in modo che solo sulla home non copaia lo backgroud ... le altre randomico e ogni 14 secondi cambia..