Crystal Report does not show report and Events of Page do not work

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C#

ASP.NET

WebForms

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i face a typical problem, when i add Crystal Report Viewer on my Aspx Page,it does not show any report, otherwise some Events (like selected index change, text change and Check changed) of this web page do not work. Even i set post back is true and all the code in Update Panel. please guide me guys. thanx in advance
here is my Report Preview source code:

object vMonth1 = null;
object vYear1 = null;
object vDate = null;
object vDate1 = null;
object vDay = null;
object vMonth = null;
object vYear = null;
object vDay1 = null;
Ledger objReport = new Ledger();
frmReportViewer1 objreportviewer = new frmReportViewer1();
 object vSelectionFormula = null;
 vDate = System.Convert.ToString(TxtFromDate.Text);
 vDay = System.Convert.ToString(System.Convert.ToDateTime(vDate).Day);
 vMonth = System.Convert.ToString(System.Convert.ToDateTime(vDate).Month);
 vYear = System.Convert.ToString(System.Convert.ToDateTime(vDate).Year);

vDate1 = System.Convert.ToString(TxtToDate.Text);
vDay1 = System.Convert.ToString(System.Convert.ToDateTime(vDate1).Day);
vMonth1 = System.Convert.ToString(System.Convert.ToDateTime(vDate1).Month);
vYear1 = System.Convert.ToString(System.Convert.ToDateTime(vDate1).Year);

ReportDocument objReports = (ReportDocument)MethodClass.ConnectionForReports(objReport);

 vSelectionFormula = "{GrnQuery.GrnDate1}" + " in date(" + vYear.ToString() + "," + vMonth.ToString() + "," + vDay.ToString() + ") to date(" + vYear1.ToString() + "," + vMonth1.ToString() + "," + vDay1.ToString() + ")";

objreportviewer.CrystalReportViewer1.SelectionFormula = vSelectionFormula.ToString();
objreportviewer.CrystalReportViewer1.ReportSource = objReport;
objreportviewer.CrystalReportViewer1.RefreshReport();