Hi,

Try this below code

in ASPX page

 <script type="text/javascript">

        function WebMonthView1_Click(oScheduleInfo, oEvent, element) {

           // var scheduleInfo = ig_getWebScheduleInfoById("WebScheduleInfo1");

            var scheduleInfo = oScheduleInfo;

            //var element = element.valueOf;

            var activity = null;            

            var activities = scheduleInfo.getActivities();

            for (var i = 0; i < activities.length; i++) {

                if (activities[i].getSubject() == "Lunch"){

                    activity = activities[i];

                    break;

                    }

             }

        }

    </script>

   <igsch:WebScheduleInfo ID="WebScheduleInfo1" runat="server">

    </igsch:WebScheduleInfo>

    <igsch:WebMonthView ID="WebMonthView1" runat="server" WebScheduleInfoID="WebScheduleInfo1">

    <ClientEvents Click="WebMonthView1_Click" DblClick="WebMonthView1_Click" />

    </igsch:WebMonthView>

in CS file

 protected void Page_Load(object sender, EventArgs e)

    {

        Appointment app = new Appointment(this.WebScheduleInfo1);

        app.Subject = "Lunch";

        app.Description = "Lunch";

        app.Location = "Cafe";

        app.EnableReminder = false;

        app.StartDateTime = new SmartDate(DateTime.Parse(DateTime.Now.ToString()));

        app.EndDateTime = new SmartDate(DateTime.Parse(DateTime.Now.ToString()));

        WebScheduleInfo1.Activities.Add(app);

      WebMonthView1.WebScheduleInfo = WebScheduleInfo1;

    }