function show_mail_popup(elem) {
    change_mail_popup("visible", elem);
}

function hide_mail_popup() {
    change_mail_popup("hidden", null);
}

function change_mail_popup(visibility, elem) {
    var popup = document.getElementById("mail_popup");
    popup.style.visibility = visibility;
    popup.style.left = elem.style.left;
    popup.style.top = elem.style.top;
}

function send_mail() {
    var mailAddress = document.getElementById("newsletterMail").value;

    var httpRequest = get_http_request();
    httpRequest.onreadystatechange = function(){
        alert('done');
    };
    var host = window.location.href.match('http://[^/]*/');
    try {
        httpRequest.open('POST', host + 'templates/jsp/fasttv/mail/sendMail.jsp', false);
        httpRequest.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
        httpRequest.send("subject=Newsletter&body=" + mailAddress);
    } catch (e) {
        alert("Error sending mail: " + e);
    }
    hide_mail_popup();
}

function get_http_request() {
    if (window.XMLHttpRequest) { // Mozilla, Safari, ...
        return new XMLHttpRequest();
    } else if (window.ActiveXObject) { // IE
        return new ActiveXObject("Microsoft.XMLHTTP");
    }
}