voila le code html :
<html>
<title>menu2.php</title>
<head>
<script language="JavaScript"><!--
function changeliste(selNode) {
//getting selected option Bvalue attribute
var arrBValue= selNode[selNode.selectedIndex].getAttribute('BValue').split(';');
//removing all existing node in listB
var listBNode = document.getElementById('listeB');
listeBNode.innerHTML = ''; /*** lazy way, should do removeNode instead ***/
for(var i=0; i<arrBValue.length; i++){
optNode = document.createElement('option'); /*** create option node ***/
optNode.appendChild(document.createTextNode(arrBValue[i])); /*** add text to node ***/
optNode.setAttribute('value', arrBValue[i]); /*** set value ***/
listBNode.appendChild(optNode); /*** add to select ***/
}
}
--></script>
</head>
<body>
<script language="JavaScript"><!--
listemois=new Array()
listemois[0]=new Array("Choisit un mois","" )
listemois[1]=new Array(
"2","4","" )
listemois[2]=new Array(
"2","4","" )
listemois[3]=new Array(
"6","" )
--></script>
<center><h2> Index des statistiques </h2></center>
<form name="monform" action="traitement.php">
<table align=center>
<tr>
<td align=letf>Annee : </td>
<td align=left><select style="width:150" name="listeA" onchange=changeliste(this)>
<option value=0>--Choisit une annee--</option>
<option value=1>
2006</option>
<option value=2>
2005</option>
<option value=3>
2007</option>
</select>
</td></tr>
<tr>
<td></td>
<td></td>
</tr>
<tr>
<td align=letf>Mois : </td>
<td align=left><select style="width:150" name="listeB">
<option>--Choisit un mois--</option>
</select>
</td></tr>
<tr>
<td></td>
<td></td>
</tr>
<tr>
<td align=letf>Type de statistique : </td>
<td align=left><select style="width:150" name="Typestat">
<option>--Choisit une requete--</option>
<option>Requete1</option>
<option>Requete2</option>
<option>Requete3</option>
<option>Requete4</option>
<option>Requete5</option>
</select>
</td></tr>
<tr>
<td></td>
<td></td>
</tr>
<tr>
<td></td>
<td align=left><input type="Submit" value="Envoyer"></td>
</table>
</form>
<BR><BR>
</body>
</html>