a.info{
            position:relative; /*this is the key*/
            z-index:24;
            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:20em;
            border:1px solid #fff;
            background-color:#c86; color:#eee;
            text-align:left;
            padding:5px;
         }