$.ajax({
                            type: "POST",
                            dataType: "json",
                            url: "ClassName.cs/MethodName",
                            data: 'data=' + JSON.stringify(cData),
                            cache: false,
                            error: function (xhr, status) {
                                
                            },
                            success: function (data) {
                            }

[WebMethod]
        public static string MethodName(HttpContext context)
        {
            return "123";
        }