a.tt:hover{
position:relative;
z-index:23;
}
a.tt span{
display:none;
}
a.tt:hover span{
display:block;
position:absolute;
top:-10px;
left:40px;
background:#fafafa;
border:1px solid #ccc;
color:#000;
z-index:20;
width:200px;
padding:5px;
font-size:11px;
cursor:pointer;
text-decoration:none;
}