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

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

.thumbnail span{ /*CSS for enlarged image*/
position: absolute;
background-color: transparent;
padding: 1px;
left: -1000px;
border: 0px dashed gray;
visibility: hidden;
color: #ff0000;
text-decoration: none;
}

.thumbnail span img{ /*CSS for enlarged image*/
border-width: 0;
padding: 2px;
}
/**
.thumbnail:hover span{  
visibility: visible;
top: -300px;
left: -180px;  
}
*/