.hidden_tooltip {
    display:none;
}

span.visible_tooltip {
    display:block;
    position:absolute;
    top:10px;
    left:21px;
    width:300px;
    font-size:9px;;
    padding-left:5px;
    padding-right:5px;
    border:1px solid black;
    background-color:#FFFFCC;
    text-decoration:none;
    color:#000000;
    z-index:10;
} 

a{  
    text-decoration:none;
}
span {
z-index=100;
}
img, table{
z-index:1;
}

.tooltipSource {
    position:relative;
}