how to show a success message when ajax called successfully

1- "beforeSend" event used to execute something before ajax call
2- "complete" event used to execute something after the ajax called successfull.

url: ' @Url.Action("AttendanceUpdateLate", "Attendance")',
data: { Emp: $("#txtEmpid").val(), Status: $("#ddlAttendance").val(), day: $("#ddlday").val(), Month: $("#Month").val() },
datatype: "json",
type: "POST",
contenttype: 'application/json; charset=utf-8',
async: true,
success: function (data) {
beforeSend: function () {
alert("Alert showing before AJAX call");
complete: function () {
alert("Alert showing after AJAX call successfully");
error: function (xhr) {
alert('error occured');