function checkForm(form, fields) {

    for (var i = 0; i < fields.length; i++)
    {
        if (form.elements[fields[i]].value == "")
        {
            window.alert("Please fill in " + fields[i] + "!");
            return false;
        }
    }

    return true;
}

function winOpen(adr, lang) {

    window.open("/template/include/content/showAdress.jsp?language=" + lang + "&adress=" + adr, "mail", "toolbar=no, width=200, height=75, status=no, scrollbars=no, resize=no, menubars=no, status=no");
}

function showMenu() {
    document.getElementById('m').style.visibility = 'visible';
}

function hideMenu() {
    document.getElementById('m').style.visibility = 'hidden';
}

function checkLettersForm(form, msg) {

    if (form.elements['american'].checked == false && form.elements['european'].checked == false) {
        window.alert(msg);
        return false;
    }

    return true;
}