Call server side function using JQuery/JSON

<script src="App_Script/jquery-1.4.3.min.js" type="text/javascript">

</script>

<script type="text/javascript">

        $(document).ready(function () {

            $("#<%= btnLogin.clientID %>").click(function () {

                    $.ajax({

                        type: "POST",

                        url: "server-side.aspx/GetCategory",

                        data: "{}",

                        contentType: "application/json; charset=utf-8",

                        dataType: "json",

                        async: true,

                        cache: false,

                        success: function (msg) {

                            $('#msg').text(msg.d);

                        },

                        error: function (data) { alert("Error" + data.d); }

                    })

                    return false;

               

             });

        });

   

</script>

HTML

<div id="msg">

 </div>

 <asp:Button runat="server" ID="btnLogin" />

C#

[WebMethod]

public static string FillRelatedCategory1 ()

{

        return " success";

}