How to pass modal window data to servlet page?

Question

I have a .jsp page with button inside. In jsp page After button click a modal popup window appear with some required blank fields. After fill up, I need pass those values to a servlet page. I know how to pass jsp page data to servlet but through model popup window i need to know. How can I do that can anyone help me out? Also i need to refresh the popup after pressing confirm button. Here is my sample code.

<div class="container">
    <div class="row" style="margin-top: 20px">

        <div class="col-md-12">

            <div class="modal fade" id="modalContactForm" tabindex="-1"
                role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
                <div class="modal-dialog" role="document">
                    <div class="modal-content">

                        <div class="modal-header">
                            <h3 class="text-primary">CUSTOMER DETAILS</h3>


                            <button type="button" class="close" data-dismiss="modal">

                                &times;</button>

                        </div>
                        <div class="modal-body mx-3">

                            <form name="DetailForm" method="post" action="HomeController">


                                <div class="row">
                                    <div class="col-md-6">
                                        <div class="form-group">

                                            <input type="text" name="txtName" id="txtName"
                                                class="form-control" placeholder="Name *" value="" />


                                        </div>
                                        <div class="form-group">
                                            <input type="email" name="txtEmail" class="form-control"
                                                placeholder="Email-id *" value="" />
                                        </div>




                                        <div class="text-center">
                                            <input type="submit" id="submitForm" data-dismiss="modal"
                                                style="font-size: 12px; color: black;" name="btnSubmit"
                                                class="btnContact" value="Confirm" />
                                        </div>



                                    </div>

                                </div>

                            </form>
                        </div>


                    </div>
                </div>
            </div>

        </div>

    </div>

</div>
<div class="text-center">

    <button type="submit" data-toggle="modal"
        data-target="#modalContactForm" class="btn">Add Complain</button>


</div>