// oSelect = <select> ; level = niveau hierarchie
function request(oSelect, level) {
	
	var cache = getElementsByClassName("cache");
	// cache les catégories lors d'un change
	for(i=(level+1); i<=3; i++)
	{
		// cache le cate +1
		var element = document.getElementById("cate"+i);
		element.style.display = "none";
		
		// boucle tant qu'un enfant existe
		while (element.firstChild) {
			// le supprime
			element.removeChild(element.firstChild);
		}
	}
	
	// valeur <select>
	var oSelect = oSelect.options[oSelect.selectedIndex];
	var value = oSelect.value;
	var nom = oSelect.firstChild.nodeValue;
	
	// objet xhr (init)
	var xhr   = getXMLHttpRequest();
	
	xhr.onreadystatechange = function() {
		if (xhr.readyState == 4 && (xhr.status == 200 || xhr.status == 0)) {
			readData(xhr.responseXML, level);
			document.getElementById("loader").style.display = "none"; // cache loader
		} else if (xhr.readyState < 4) {
			document.getElementById("loader").style.display = "inline"; // affiche loader
		}
	};
	
	xhr.open("POST", "traitementCategorie.php", true);
	xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
	xhr.send("id="+value+"&level="+level);
}

unction readData(oData, level) {
	var nodes = oData.getElementsByTagName("item");
	
	if(nodes.length>1)
	{
	document.getElementById("cate"+(level+1)).style.display = "inline";


	var oSelect = document.getElementById("cate"+parseInt(level+1));
	var oOption, oInner;
	
	for (var i=0, c=nodes.length; i<c; i++) {
		oOption = document.createElement("option");
		oInner  = document.createTextNode(nodes[i].getAttribute("name"));
		oOption.value = nodes[i].getAttribute("id");
		
		oOption.appendChild(oInner);
		oSelect.appendChild(oOption);
		}
	}
}