private int checkmk() { int kq = 0; BUSGiaoVien mk = new BUSGiaoVien(); string mktemp = mk.LayMatKhau(IDNguoiDung); mktemp = mktemp.Replace(" ", ""); if (mktemp == ToMD5(tb_QT_MKC.Text)) { kq = 1; } return(kq); }