#bubble {
    list-style: none;
    margin: 0px 0px 0px;
    padding: 0px;
}
#bubble li {
    display: inline-block;
    margin: 0px 0px;
    padding: 0px;
    width: 93px;
    height: 24px;
}
#bubble li a img {
    position: relative;
    border: none;
}

#bubble li a img#big {
    display: none;
}

#bubble li a:hover img#small {
    display: none;
    z-index: 0;
}

#bubble li a:hover img#big {
    position:absolute;
    display: block;
    margin-top: 0px;
    margin-left: -13px;
    z-index: 1000;
}