//function add(){alert ("aaa");}
function getXhr()
{ 
  var xhr = null;
  try { xhr = new ActiveXObject('Msxml2.XMLHTTP'); 
}
catch (e1)
{
  try { xhr = new ActiveXObject('Microsoft.XMLHTTP'); }
  catch (e2)
{
  try { xhr = new XMLHttpRequest(); }
  catch (e3)
{
  alert("AJAX n'est pas supporté par votre navigateur");
  return false;
}
}
}
return xhr;
}

function add_admin()
{
var nom    = document.getElementById('nom').value;
var prenom = document.getElementById('prenom').value;
var email  = document.getElementById('email').value;
var prenom = document.getElementById('login').value;
var pwd  = document.getElementById('pwd').value;

var params += '?nom=' + encodeURIComponent(nom);
    params += '&prenom=' + encodeURIComponent(prenom);
    params += '&email=' + encodeURIComponent(email);
    params += '&login=' + encodeURIComponent(login);
    params += '&pwd=' + encodeURIComponent(pwd);

var xhr = getXhr();
xhr.onreadystatechange = function()
{
if (xhr.readyState == 4 && xhr.status == 200)
 document.getElementById("result").innerHTML = xhr.responseText;
//xhr.responseText
else  document.getElementById("result").innerHTML = "error";
var url = 'add_traitement.php' + params;
xhr.open('GET', url, true);
xhr.send();
}
</script>