.thumbnail {
    position: relative;
    z-index: 0;
}

.thumbnail:hover {
    background-color: transparent;
    z-index: 50;
}

.thumbnail span { /*CSS for enlarged image*/
    position: absolute;
    background-color: lightyellow;
    padding: 5px;
    left: -1000px;
    border: 1px dashed 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;
	position:relative;;
    left: -60px; 
    top: -200px;

    /*position where enlarged image should offset horizontally */
}