private void updateGrade()
        {
            try
            {
                if (!txtGradeId.Text.Trim().Equals(string.Empty))
                {
                    GradeDTO oGradeDTO = new GradeDTO();
                    oGradeDTO.GradeId          = Convert.ToInt16(txtGradeId.Text.Trim());
                    oGradeDTO.SubjectId        = cmbSubject.SelectedValue.ToString();
                    oGradeDTO.Description      = txtDescription.Text.Trim();
                    oGradeDTO.LowerLimit       = Convert.ToInt16(txtLowerLimit.Text.Trim());
                    oGradeDTO.UpperLimit       = Convert.ToInt16(txtUpperLimit.Text.Trim());
                    oGradeDTO.ModifiedBy       = "Kaveen";
                    oGradeDTO.ModifiedDateTime = DateTime.Now;

                    if (oGradeBL.UpdateGrade(oGradeDTO))
                    {
                        ClearControls();
                        filterBySubjectId();
                        MessageBox.Show("Record Updated successfully.!");
                    }
                }
                else
                {
                    txtGradeId.Focus();
                }
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }