#fb {
    position: fixed;
    bottom: -500px;
    left: 20px;
    z-index: 9999;
    padding-top: 10px;
}

#fb_close {
    position: absolute;
    top: -10px;
    background: url(images/close.png) center center no-repeat;
    width: 72px;
    height: 10px;
    cursor: pointer;
}