a.info
{
position:relative; /*this is the key*/
z-index:24;
background-color:#ccc;
color:#000;
text-decoration:none
}


a.info:hover
{
z-index:25;
background-color:#ff0
}


a.info span
{
display: none
}


a.info:hover span
{
/*the span will display just on :hover state*/
display:block;
position:absolute;
top:2em; left:2em; width:15em;
border:1px solid #0cf;
background-color:#cff;
color:#000;
text-align: center
}