C#.NET - Adding "SELECT" in Combo box

private void LoadCommentType()

        {

            try

            {

                DataTable dtCommentType = clsCommon.oAdmin.dtGetCommentType();

                if (dtCommentType != null)

                {

                    DataRow dr = dtCommentType.NewRow();

                    dr["CommentTypeId"] = 0;

                    dr["CommentTypeName"] = "--Select--";

                    dtCommentType.Rows.InsertAt(dr, 0);

                    cboComment.DisplayMember = "CommentTypeName";

                    cboComment.ValueMember = "CommentTypeId";

                    cboComment.DataSource = dtCommentType.DefaultView;

                }

            }

            catch (Exception ex)

            {

                ExceptionHandler.HandleException(ex.ToString());

            }

        }