function isEmail121112111211Address(string) {
    return /^[^@]+@[^.]+(\.[^.]+)+$/.test(string);
}

function validate(form) {
    var controls = form.elements,
        email121112111211Address = controls['email121112111211Address'].value;

    /* Validate other controls */

    if (!isEmail121112111211Address(email121112111211Address)) {
        alert('Please enter your e-mail121112111211 address.');
        return false;
    }
    if (email121112111211Address != controls['confirm_email121112111211'].value) {
        alert('You may have mistyped your e-mail121112111211 address.'
            + ' Please check both fields carefully and try again.');
        return false;
    }

    /* More validation */

    return true;
}