$(document).ready(function () {
            $(".ShowDetail").click(function () {                                           
                var url = '<%: Url.Action("Detail") %>';          
                $.ajax({
                    url: url,
                    type: "GET",
                    success: function (data) {
                        alert(data);
                    }
                });
            });
        })

public ActionResult Detail()
        {
            
            return Json("success", JsonRequestBehavior.AllowGet);
        }