<html>
<head>
    <script>
        function test()
        {
            var div = document.createElement("div");
            document.body.appendChild(div);
            document.body.removeChild(document.body.lastChild);
        }
    </script>
</head>
<body onload="test()">
    <div style="display: inline-block; width: 100px; height: 100px; background: red;">
        <div style="width: 100px; height: 100px; background: green; opacity: 0.9;">
        </div>
    </div>
</body>
</html>