.thumbnail{
position:relative;
z-index:0;
}
.thumbnail:hover{
background-color:transparent;
z-index:50;
}
.thumbnail span{
-moz-border-radius:10px;
border-radius:10px;
position:absolute;
background-color:#ffffff;
padding:5px;
top:0;
left:-2000px;
border:1px solid #cccccc;
visibility:hidden;
color:black;
text-decoration:none;
background-color:lightyellow;
font-weight:bold;
}
.thumbnail span img{
border-width:0;
padding:2px;
}
.thumbnail:hover span{
visibility:visible;
top:0;
left:50px;
}