... cung", 64, "Thong bao" Me.toi.Enabled = False Me.cuoi.Enabled = FalseEnd SubPrivate Sub cuoi_Click()On Error GoTo Err_cuoi_Click Me.MAKH.SetFocus Call cuoirec Trang 4 Me.toi.Enabled ... True Me.cuoi.Enabled = True Exit SubErr_lui_Click: MsgBox "Da den mau tin dau tien", 64, "Thông Báo" Me.dau.Enabled = False Me.lui.Enabled = FalseEnd SubPrivate Sub toi_Click()On ... = True Me.TGTONDAUKY.Locked = True Exit SubErr_huy_Click: MsgBox "Huy thao tac", 64, "Thong bao" Me.huy.Visible = False Me.luu.Visible = False Me.moi.Visible = True...