var request = false;
try {
    request = new XMLHttpRequest();
} catch (trymicrosoft) {
    try {
        request = new ActiveXObject("Msxml2.XMLHTTP");
    } catch (othermicrosoft) {
        try {
            request = new ActiveXObject("Microsoft.XMLHTTP");
        } catch (failed) {
            request = false;
        }
    }
}

if (!request)
    alert("Error initializing XMLHttpRequest!");

function RequestCallback(juri) {
    var frm = document.callbackForm;
    var name = frm.name.value;
    var email = frm.email_address.value;
    var phone = frm.phone_number.value;

    if ((name == '') || (name == 'Name')) {
        document.getElementById('callbackFeedback').innerHTML = 'You must enter a name';
        return;
    }

    if (((email == '') || (email == 'Email')) && ((phone == '') || (phone == 'Phone'))) {
        document.getElementById('callbackFeedback').innerHTML = 'You must enter at least one method of communication';
        return;
    }

    var url = juri + "modules/mod_callbackform/assets/mod_callbackform_script.php";
    var params = "name=" + name + "&email=" + email + "&phone=" + phone;
    request.open("POST", url, true);
    request.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
    request.setRequestHeader("Content-length", params.length);
    request.setRequestHeader("Connection", "close");
    request.onreadystatechange = function() {
        if (request.readyState == 4 && request.status == 200) {
            var response = request.responseText;
            document.getElementById('callbackFeedback').innerHTML = response;
        }
    }

    request.send(params);
}