.thumbnail{
    position: relative;
    z-index: 0;
    }
.thumbnail:hover{
    background-color: transparent;
    z-index: 50;
    }
.thumbnail span{ /*CSS for enlarged image*/
    position: absolute;
    background-color: #999999;
    padding: 5px;
    left: -1000px;
    border: 1px gray;
    visibility: hidden;
    color: black;
    text-decoration: none;
    }
.thumbnail span img{ /*CSS for enlarged image*/
    border-width: 0;
    padding: 2px;
    }
.thumbnail:hover span{ /*CSS for enlarged image on hover*/
    visibility: visible;
    top: 0;
    left: 60px; /*position where enlarged image should offset horizontally */
    }