#box a 
	{
	text-decoration:none;
	display:block;
	width:30px;
	padding:0px;
	}

#box a:hover
	{
	border:0px;
	}

#box a span 
	{
	display:none;
	}

#box a:hover span 
	{
position: absolute; 
display: block;
	text-align: left;
	width: 100px;
	color: black;
	background: #ffffff;
	font: normal 10px Verdana, Geneva, Arial, Helvetica, sans-serif;
	border: 1px solid black;
	padding: 10px;
}

<div id="box"><a href="index.php?content=profil&section=profil&uid=<? echo $u_data['id']; ?>"><? echo $u_data['benutzername']; ?><span>Profil
Short Message
add buddy</span></a></div>