function submitBookingForm() {
    var form = document.forms["bookingForm"];
    var error = "";
    var name = form.elements["name"].value;
    if(name == "") {
        error += "\nName";
    }
    var email = form.elements["email"].value;
    if(email == "") {
        error += "\nE-mail";
    }
    var phoneNumber = form.elements["phoneNumber"].value;
    if(phoneNumber == "") {
        error += "\nPhone Number";
    }
    if(error != "") {
        alert("Please fill out following fields:" + error);
    } else {
        form.submit();
    }

}