a.info{
     position:relative; /*this is the key*/
#    z-index:1;
#    background-color:#ccc;
     color:#000;
     font-size: 80%;
     text-decoration:none}

#a.info:hover{z-index:25; background-color:#99CCFF}

a.info span{display: none}

a.info:hover span{ /*the span will display just on :hover state*/
     display:block;
     position:absolute;
     top:1em; left:0em; width:10em;
     border:3px solid #99CCFF;
     background-color:#99CCFF; color:#000; z-index:1;
     text-align: left}