#gallery_container {
    width: 290px;
    height: 290px;
}
div.image_container {
    position: absolute;
    z-index: 1000;
}
div.image_container a {
    border: 1px solid red;
    margin: 0;
    display: block;
    float: left;
}
div.image_container a {
    border: 0;
    margin: 0;
    display: block;
    float: left;
}
div.image_container a img{
    display: block;
    border: 0px;
}