.gallerycontainer {
    position: relative;
    /*Add a height attribute and set to largest image's height to prevent overlaying*/
}

.thumbnail:hover {
    background-color: transparent;
}

    .thumbnail:hover img {
        border: 0px none white;
    }

.thumbnail span { /*CSS for enlarged image*/
    position: absolute;
    background-color: #ffffff;
    border: 1px solid #EEEEEE;
    visibility: hidden;
    padding: 5px;
    display: table-cell;
}

    .thumbnail span img { /*CSS for enlarged image*/
        /*
            max-height:120px;
            max-width:120px;
        */
    }

.thumbnail:hover span { /*CSS for enlarged image*/
    visibility: visible;
    top: 0px;
    left: 20px; /*position where enlarged image should offset horizontally */
    z-index: 50;
}