function valid(form){

    var error = false;

    var email = form.email.value;

    var phone = form.phone.value;

        if(email == "" || email == " ")

            error = "Вы не ввели email";

        else if (phone == "")

            error = "Вы не ввели телефон";

        if(error)

            alert(error);

}