a.hastooltip { border-bottom: 1px dotted #00aa00; color: #000000; cursor: help; font-style: normal; position: relative; /* This is the key */ text-decoration: none; z-index: 24; /* What does this do? */ } a.hastooltip:active { color: #000000; text-decoration: none; } a.hastooltip:link { color: #000000; text-decoration: none; } a.hastooltip:hover { background-color: #a0b8ff; color: #000000; text-decoration: none; z-index: 25; } a.hastooltip:visited { color: #000000; text-decoration: none; } a.hastooltip span { display: none; } a.hastooltip:hover span { background-color: #eeeeee; border: 1px solid #000000; color: #000000; display: block; padding: 5px; left: -15.2em; position: absolute; text-align: center; text-decoration: none; top: 2em; width: 20em; }