private void BindData() { using (var helper = new DbHelper.Subject()) { var levelId = Convert.ToInt32(cmbLevel.SelectedValue == ""?"0":cmbLevel.SelectedValue); var subjects = helper.ListSubjects(levelId); grdView.DataSource = subjects; grdView.DataBind(); //grdView.Columns.Add(new datacontrolfie); = ""; } }