Наследование: System.Windows.Forms.Form
        private void m_cmd_dm_he_so_luong_ns_ItemClick(object sender, ItemClickEventArgs e)
        {
            try
            {
                DanhMuc.F103_dm_he_so_luong_ns v_frm = new DanhMuc.F103_dm_he_so_luong_ns();
                if(IsExistFormName(v_frm)) return;

                v_frm.MdiParent = this;
                v_frm.Show();
            }
            catch(Exception v_e)
            {
                CSystemLog_301.ExceptionHandle(v_e);
            }
        }