How to Call Function in Client/Designing Side in asp.net?

Cliet Side

<asp:ListView ID="ListView3" runat="server">

     <LayoutTemplate>

         <tr id="ItemPlaceholder" runat="server">

         </tr>

     </LayoutTemplate>

     <ItemTemplate>

          <tr class="odd gradeX">

              <td>

                    <a href="#myModal1" role="button" data-toggle="modal">Anonymous Responses(<asp:Label ID="Label4" runat="server" Text='<%# Respons(Eval("ID").ToString()) %>'></asp:Label>)</a>

               </td>

          </tr>

     </ItemTemplate>

</asp:ListView>

Server Side

public string Respons(string ID)

        {

            string CID = "V" + ID.ToString();

            return DB.Responses.Where(p => p.CategoryID == CID).Count().ToString();

        }