form.tao-form {
    position: relative;
}

    form.tao-form div.shadow {
        position: absolute;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background-color: #eee;
        background-image: url(/tao/images/loader2.gif);
        background-repeat: no-repeat;
        background-position: center center;
        opacity: 0.8;
    }