Salut,
<html>
<head>
<script type="text/javascript">
function change(a){
if(a == 1)
document.getElementById("imag").src = "ap.bmp";
else
document.getElementById("imag").src = "dep.bmp";
}
</script>
</head>
<body>
<a href="#" onclick="change(1);">Après</a><br>
<a href="#" onclick="change(0);">Départ</a><br>
<img src="dep.bmp" id="imag">
</body>
</html>
@++