Error in report ... [modified]

[mostafa_h]

hi all , In Report Page , I suppressed on the sepecified field(e.g :"firstname") on Common Tab in Format Object .I checked CheckBox1 in Form1 for showing field("firstname")on the Table . in Form1.cs in btnShow_Click , I wrote this : ... LoadData(); if(CheckBox1.Checked) myCrystalReport1.ReportDefinition.Sections[1].ReportObjects["firstname1"].ObjectFormat.EnableSuppress = false; It works for several times , but Sometimes , I have this Error : A callback was made on a garbage collected delegate of type 'CrystalDecisions.ReportAppServer.DataSetConversion!CrystalDecisions.ReportAppServer.DataSetConversion.DataSetConverter+CrdbAdoPlusDelegate::Invoke'. This may cause application crashes, corruption and data loss. When passing delegates to unmanaged code, they must be kept alive by the managed application until it is guaranteed that they will never be called. Or with This Error : Value does not fall within the expected range. plz help me Thanks

s_mostafa_h