Popup Window using Script in asp.net

<link type="text/css" rel="stylesheet" href="http://code.jquery.com/ui/1.10.3/themes/smoothness/jquery-ui.css" />

<script type="text/javascript" src="http://code.jquery.com/jquery-1.8.2.js"></script>

<script type="text/javascript" src="http://code.jquery.com/ui/1.10.3/jquery-ui.js"></script>

<script type="text/javascript">

        $(function () {

            debugger;

            $('#<%=btnclick.ClientID%>').click(function () {

                $("#popupdiv").dialog({

                    appendTo: "form",

                    title: "jQuery Popup from Server Side",

                    width: 500,

                    height: 280,

                    modal: true,

                    bgiframe: false,

                   

                });

                return false;

            });

        })

    </script>

<asp:Button ID="btnclick" runat="server" Text="Add " />

<div id="popupdiv" title="Basic modal dialog" style="display: none">

                           

   <div class="row">

      <div class="col-md-3">

        image

      </div>

      <div class="col-md-7">

        <asp:FileUpload ID="FileUpload1" runat="server" />

      </div>

   </div>

   <div class="row" style="margin-top: 54px;"></div>

      <div class="row" style="margin-left: 200px">

         <asp:Button ID="btnUpload" runat="server" Text="Upload" UseSubmitBehavior="false"                          OnClick="btnUpload_Click" />                          

      </div>              

  </div>

</div>

using System.IO;

protected void btnUpload_Click(object sender, EventArgs e)

        {

            if (FileUpload1.HasFile)

            {

                string fileName = Path.GetFileName(FileUpload1.PostedFile.FileName);

                FileUpload1.PostedFile.SaveAs(Server.MapPath("~/image/") + fileName);

                string v = "~/image/" + fileName;

            }