SelectedDateChanged is not working on Dynamic DatePicker?

Question

I have a Dynamic DatePicker and i want call SelectedDateChanged event but its not working/firing?? Although i have used same code on a sample applicaion and its working fine there but in my application its not working?? Can any one tell me what are possible reasons for that?? here is my code

        else if (_db.DbProviderFactory.ToString().Contains("OracleClient"))
        {
            RadDatePicker mtb = new RadDatePicker();
            mtb.ID = "MTB" + _caption.Replace(" ", "_").ToUpper();
            string id="MTB" + _caption.Replace(" ", "_").ToUpper();;
            mtb.EnableViewState = false;
            mtb.Attributes.Add("runat", "Server");
            mtb.SelectedDate = DateTime.Now;

            // Both Event
            mtb.Attributes.Add("onchange", "oraProcessDate('" +        "ctl00_ContentPlaceHolder1_" + mtb.ID + "'," + n + "); return false;");
            mtb.Attributes.Add("onblur", "oraProcessDate('" + "ctl00_ContentPlaceHolder1_" + mtb.ID + "'," + n + "); return false;");
            mtb.AutoPostBack = true;
            //mtb.SelectedDateChanged += new Telerik.Web.UI.Calendar.SelectedDateChangedEventHandler(mtb_SelectedDateChanged);
            mtb.SelectedDateChanged += new Telerik.Web.UI.Calendar.SelectedDateChangedEventHandler(pckDate_SelectedDateChanged);
            //rdp.SelectedDateChanged += new SelectedDateChangedEventHandler(rdp_SelectedDateChanged); 
           // mtb.AutoPostBack = true;
            //this.mtb.+= new EventHandler<SelectionChangedEventArgs>(datePicker_SelectedDateChanged);
            //mtb.SelectedDateChanged += new SelectedDateChangedEventHandler(mtb_changed);
            //mtb.SelectedDateChanged+=
            mtb.Width = 200;
            tc.Controls.Add(mtb);
            tc.Style.Add("width", "35%");
            tr.Cells.Add(tc);
            ValidateFields(n, _requirefield.ToString());
            mtb.SelectedDateChanged += new Telerik.Web.UI.Calendar.SelectedDateChangedEventHandler(pckDate_SelectedDateChanged);
        }
    }


    protected void pckDate_SelectedDateChanged(object sender, Telerik.Web.UI.Calendar.SelectedDateChangedEventArgs e)
    {
        lblMessage.Text = "testttttttting";

    }