a.infobulle {
position: relative;
}

a.infobulle span {
display: none;
}

a.infobulle:hover {
background: none;
z-index: 999;
}

a.infobulle:hover span {
display: inline;
position: absolute;
white-space: nowrap;
right: 20px;
background-color: white;
color: white;
padding: 3px;
border: 1px dashed white;
}

.pseudo {
letter-spacing: 2px;
text-transform: none;
border-bottom: 2px blue dashed;
color: red;
width: 65%;
}

.titre {
letter-spacing: 2px;
text-transform: none;
border-bottom: 2px blue dashed;
color: red;
border-bottom: 1px black dashed;
}

.profil {
text-transform: uppercase;
letter-spacing: 2px;
color: white;
border-bottom: 2px dashed blue;
}

.mp {
text-transform: none;
letter-spacing: 2px;
color: white;
border-bottom: 2px dashed blue;
}

<table border="0" width="100%" align="center" summary="La page d'acceuil">
<tr>
<td valign="top" widht="30%"><div class="staff">L'Equipe</div>
<a href="PROFIL.html" class="infobulle"><p class="pseudo">~ xNeko ~</p>
<span>
<img src="http://i68.servimg.com/u/f68/15/08/74/08/1-8510.jpg"><br><p class="titre">FONDATEUR</p><div><a href="profil.html" target="_blank" class="profil">PROFIL</a></div><div><a href="mp.html" class="mp">MP</a></div></span>
</td>
<td valign="top" width="40%"><div class="description">welcome</div>
<br><marquee align="center" scrollAmount="1" direction="down" style="width: 365px; height: 100px" class="defilement">TEXTE TEXTE TEXTE TEXTE TEXTE TEXTE TEXTE TEXTE TEXTE TEXTE TEXTE TEXTE</marquee>
</td>
<td valign="top" widht="30%"><div class="navigation">Navigation</div>
</tr>
</table>