I have a for loop that call a ajax method
function viderTableauConteneur()
{
    var caf =  document.getElementById('CAF').value;
    var tabConteneurAjouter = caf.split("#"); 
    for (var i = 0; i < tabConteneurAjouter.length; i++) {
        if(!verifierConteneurAppartienClient(tabConteneurAjouter[i]));
            removeConteneur(tabConteneurAjouter[i]);
    };
}
function verifierConteneurAppartienClient(serialNumber)
{
    var e = document.getElementById("id_client");
    var idClient = e.options[e.selectedIndex].value;
    var xhr = getXhr();
    var res = 12;
    xhr.onreadystatechange = function()
    {
        if(xhr.readyState == 4 && xhr.status == 200)
        {
            if(xhr.responseText == "0")
                return false;
            else if(xhr.responseText == "1")
                return true;
        }
    }
    xhr.open("GET","index.php?option=com_tkcontrack&controller=facture&task=verifierConteneurAppartienClient&refConteneur="+serialNumber+"&id_client="+idClient,true);
    xhr.send();
}
Well if I alert the xhr.responseText I got "1", but when I alert the result in the viderTableauConteneur method I always got "Undifined"
Any help please
 
    