在PgwModal内部序列化返回空值

Question

我希望用户能够在模态（pgwmodal.js）中注册自己。序列化表单会返回带有空值的键，即使它们已填入。

HTML

<div id="modal-register" style="display: none;">
    <div class="row">
        <form method="post">
            <div class="input width_50">
                <label for="register_input_first_name">Name</label>
                <input type="text" name="register_input_first_name" id="register_input_first_name">
                <input type="text" name="register_input_last_name" id="register_input_last_name">
            </div>
            <div class="input">
                <label for="register_input_email">Email</label>
                <input type="text" name="register_input_email" id="register_input_email">
            </div>
            <div class="input">
                <label for="register_input_password">Password</label>
                <input type="password" name="register_input_password" id="register_input_password">
            </div>
            <div class="input">
                <button id="button_register" type="button" class="button button-primary">Create user</button>
            </div>
        </form>
    </div>
</div>

的jQuery

jQuery(document).ready(function($) {

    // create modal
    $('.register-trigger').click(function() {
        $.pgwModal({
            target: '#modal-register',
            title: 'New user',
            maxWidth: 970
        });
    });

    // serialize when button is clicked
    $(document).on("click", "#button_register", function() {
        console.log($('#modal-register form').serialize());
        $.post("functions/func_register.php",$('#modal-register form').serialize(),
        function(data) {
            console.log(data);
        }, 'json');
    });

});

我想我不知何故需要用模态的内容更新#modal-register。如果我填写表单的每个字段，序列化函数会给出以下响应：

register_input_first_name =安培; register_input_last_name =安培; register_input_email =安培; register_input_password =