<html>
<head>
<style>

body {
    height:2000px;
    margin:0;
    overflow:hidden;
}

#fixed-background-box {
    width:400px;
    height:600px;
    background-image:url(resources/green.png);
    background-attachment:fixed;
}

</style>

<script>
function runTest() {
    if (window.internals)
        window.internals.setTopContentInset(100);
    window.scrollTo(0, 100);
}

window.addEventListener('load', runTest, false);
</script>
</head>

<body>

<div id="fixed-background-box"></div>

</body>
</html>