a.bouton:link{
width:150px; 
height:30px; 
text-decoration:none; 
color:white;
text-align:center; 
font-weight:bold; 
background-color:#000080;
padding:5px}

a.bouton:visited{
width:150px; 
height:30px;
text-decoration:none; 
color:white; 
text-align:center;
font-weight:bold;
background-color:#000080;
padding:5px}

a.bouton:hover{
width:150px; 
height:30px; 
text-decoration:none;
color:white; 
text-align:center; 
font-weight:bold; 
background-color:#0000FF;
background-image:url(aqua.jpg);
padding:5px}

.bouton{text-align:center;padding:5px;}