I have the following Javascript code that fills an array in a PHP doc:
function getOptions(scheme)
{
    var url = "options.php?scheme=" + scheme;

    if (xmlHttpObj)
    {
        xmlHttpObj.open("GET", url, true);

        xmlHttpObj.onreadystatechange=function()
        {
            if (xmlHttpObj.readyState == 4 &&
                xmlHttpObj.status == 200 || xmlHttpObj.status == 304)
                    {
                        var xmlDocument = xmlHttpObj.responseXML;
                        options = xmlDocument.getElementsByTagName("option");
                        listOptions();
                    }
        }

        xmlHttpObj.send(null);
    }
}

The php looks like this:
<?
    header("Content-type: text/xml");

    if ($_GET["scheme"] == "1")
        $options = array('red', 'green', 'blue');
    if ($_GET["scheme"] == "2")
        $options = array('black', 'white', 'orange');

    echo '<?xml version="1.0"?>';
    echo '<options>';
    foreach ($options as $value)
    {
        echo '<option>';
        echo $value;
        echo '</option>';
    }
    echo '</options>;

?>

I call the function OK, but always get a readyState of 1.

Any ideas anyone?