Keep Bootstrap modal open if validation error is raised using jQuery in ASP.Net

hi

how to use modal in bootstrap

Here I use requiredfieldvalidator when users enter wrong information and click button it will shows an Error

Problem is that when I enter wrong information and click button Modal popup closed and I should again click on ContactUs from menu to show Modal and see Error:

I want when I click button it doesn't close Modal...

What should I do?

I use Modal (bootstrap) in my page below are codes:

    <script type="text/javascript">
        $(function () {
            $('#TH5L1LPMV').hide();
            $('#TH5L1LPMPM').hide();
            $('#TH5L1LPM11').show();
            $('#TH5L1LPM2').hide();
            $("#navbarNav li a").click(function () {
                if ($(this).text() == "Pricing") {
                    $('#myModal').modal('show');
                }
                if ($(this).text() == "ContactUs") {
                    $('#myModal1').modal('show');
                }
            });
        });
    </script>
<div id="collapse">
    <nav class="navbar navbar-expand-lg navbar-light bg-light">
      <a class="navbar-brand" href="#"></a>
      <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation">
        <span class="navbar-toggler-icon"></span>
      </button>
      <div class="collapse navbar-collapse" id="navbarNav">
        <ul class="navbar-nav">
          <li class="nav-item active">
            <a class="nav-link">About Us</a>
          </li>       
             <li class="nav-item">
            <a class="nav-link">Contact Us</a>
          </li>
        </ul>
      </div>
    </nav>
</div>
<div class="modal fade" id="myModal1">
    <div class="modal-dialog">
        <div class="modal-content">
            <!-- Modal Header -->
            <div class="modal-header">
                <div id="btnclose">
                    <button type="button" class="close" data-dismiss="modal">&times;</button>
                </div>
                <div id="btntext">
                    <asp:label id="Label46" runat="server" cssclass="lablemodal">ContactUs</asp:label>

                </div>
            </div>
            <!-- Modal body -->
            <div class="modal-body">
                <div id="topadd2M">
                    <div id="DNCRM1">
                        <div id="DNCRM">
                            <asp:label id="Label55" runat="server" cssclass="sMalekNa1C1M"> Name:  </asp:label>

                            <asp:label id="Label56" runat="server" cssclass="sMalekNaM"> *</asp:label>

                        </div>
                        <asp:textbox id="TxtName" runat="server" cssclass="txtnameCM" tabindex="1"></asp:textbox>
                    </div>
                    <div id="DNCRM1">
                        <div id="DNCLM">
                            <asp:label id="Label57" runat="server" cssclass="sMalekNa1CM"> Email:</asp:label>
                            <asp:label id="Label58" runat="server" cssclass="sMalekNaM"> *</asp:label>

                        </div>
                        <asp:textbox id="TxtEmail" runat="server" cssclass="txtmobCM" tabindex="2"></asp:textbox>
                    </div>
                    <div id="DnameC4M">
                        <asp:textbox id="TextBox4" runat="server" cssclass="txtdesCoM" textmode="MultiLine" tabindex="5"></asp:textbox>
                    </div>
                </div>
                <div id="topadd3M">
                    <div id="DnameC6M">
                        <asp:imagebutton id="ImageButton2" runat="server" imageurl="~/Image/main/sendmessage.png" cssclass="imgSeneMeM" onclick="Imgsend_Click"></asp:imagebutton>
                    </div>
                </div>
                <div id="DnameC7M">
                    <div id="message" class="attenCCM">
                        <asp:label id="Label63" runat="server" cssclass="lblattenC1M">please enter correct information</asp:label>

                        <asp:image id="Image15" runat="server" cssclass="imgattenM" imageurl="~/Image/main/atten.png"></asp:image>
                    </div>
                    <asp:requiredfieldvalidator display="Dynamic" id="RequiredFieldValidator1" runat="server" controltovalidate="Txtname"></asp:requiredfieldvalidator>
                    <script type="text/javascript">
                        function WebForm_OnSubmit() {
                            var message = document.getElementById("message");
                            message.style.display = "none";
                            if (typeof (ValidatorOnSubmit) == "function" && ValidatorOnSubmit() == false) {
                                for (var i in Page_Validators) {
                                    try {
                                        if (!Page_Validators[i].isvalid) {
                                            message.style.display = "block";
                                        }
                                    } catch (e) {
                                    }
                                } return false;
                            } return true;
                        }
                    </script>
                    <!-- Modal footer -->
                    <div class="modal-footer">
                        <button type="button" class="btn btn-danger" data-dismiss="modal">Close</button>
                    </div>
                </div>
            </div>
        </div>
        </div>
    </div>

Best regards

Neda