Edit in JSFiddle

<a href="#" class="tooltip">
    Tooltip
    <span>
       <strong>Tooltip</strong><br />
        This is the easy-to-use Tooltip driven purely by CSS.
    </span>
</a>

<iframe id="iframe1" src="http://jqfaq.com/AdPage.html" style="width:100%; height:115px; border:none;"
/>

a.tooltip {
    outline:none;
}
a.tooltip strong {
    line-height:30px;
}
a.tooltip:hover {
    text-decoration:none;
}
a.tooltip span {
    z-index:10;
    display:none;
    padding:14px 20px;
    margin-top:-30px;
    margin-left:28px;
    width:240px;
    line-height:16px;
}
a.tooltip:hover span {
    display:inline;
    position:absolute;
    color:#111;
    border:1px solid #DCA;
    background:#fffAF0;
}