function MailFormCheck() {
    var lastname = document.getElementById('last_name');
    var company = document.getElementById('company');
    var phone = document.getElementById('phone');
    var email = document.getElementById('email');
    var description = document.getElementsByTagName('textarea')[0];
    var div = document.getElementById('missingFields');
    if (lastname.value == '' || company.value == '' || phone.value == '' || email.value == '' || description.value == '') {
        div.style.display = 'block';
        return false;
    }
    else {
        div.style.display = 'none';
        return true;
    }
}