.thumbnail{
z-index: 0;
display:block;
}

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

.thumbnail span{ /*CSS for enlarged image*/
visibility: hidden;
}

.thumbnail span img{ /*CSS for enlarged image*/
position:absolute;
border-width: 0;
padding: 2px;
}

.thumbnail:hover span{ /*CSS for enlarged image on hover*/
position:absolute;
visibility: visible;
top: 13px;
left: -2px; /*position where enlarged image should offset horizontally */
}