//mailing
function isEmpty(e) {
    return ((e == null) || (e.length == 0));
}

function isEmail(mail) {
    re = /^[_a-zA-Z0-9\.\-]+@[_a-zA-Z0-9\.\-]+\.[a-zA-Z]{2,7}$/;
    return mail.search(re) == 0;
}