{"Object reference not set to an instance of an object."}

[shanker bangari]

Hi


This is shanker I doing one report i face this error in my  reporting   {"Object reference not set to an instance of an object."} 

this is my code 

  public void rport(UserDashboard userDashboard)

        {

            var report = new MvcApplication18.Reports.RepClassList();

            var res = userDashboard;

            if (report != null)

            {

                report.DataSource = res;

                

                class_subject_teacher_list_rep.Report = report ---------------here i am getting error
;

                class_subject_teacher_list_rep.ShowExportGroup = true;

            }

        }

here i getting  all values in dashboard variable and Res varibale. But In Reportviewr Binding I face this Error 
{"Object reference not set to an instance of an object."} 


please give any solutions 

thanks and regards

shanker.b