function request(callback,id) {

	var xhr = getXMLHttpRequest();
	var button = "button" + id;
	var loader = "loader" + id;

	xhr.onreadystatechange = function() {
		if (xhr.readyState == 4 && (xhr.status == 200 || xhr.status == 0)) {
			document.getElementById(button).value = xhr.responseText;
			document.getElementById(loader).innerHTML = "";
			document.getElementById(button).style.display = "inline";
			callback(xhr.responseText,id);

		} else if (xhr.readyState < 4) {
			document.getElementById(loader).innerHTML = "<img style=\"height: 20px;\" src=\"/images/23-1.gif\" alt=\"loading\" />";
			document.getElementById(button).style.display = "none";
		}
	};
	
	xhr.open("GET", "/cacher_afficher.php?id=" + id, true);
	xhr.send(null);
}

function readData(sData,id) {
	var button = "button" + id;
	// On peut maintenant traiter les données sans encombrer l'objet XHR.
	if (sData == "Désactivé" || sData == "Email non valide") {
		document.getElementById(button).className = "vermillon";
	} else {
		document.getElementById(button).className = "gris";
	}
}