<html>
    <body>
        <div style="width: 18px; position: relative">
            <div id="t1" style="float: right; background-color: silver; width: 10px; height: 100px">
            </div>
            <div id="t2">
                <div>
                    <div style="float: right; background-color: orange; width: 5px; height: 50px"></div>
                    <div style="background-color: blue;">A B C D<div style="float: right; background-color: green; width: 5px; height: 50px"></div></div>
                </div>
            </div>
        </div>
        <script>
            document.body.offsetTop;
            t2.style.position = 'fixed';
            document.body.offsetTop;
            t2.style.position = 'static';
        </script>
    </body>
</html>