Private Sub Command1_Click()

Dim tl As String

tl = MsgBox("ban co thuc su muon thoat khong", vbQuestion + vbYesNoCancel, "bang thong bao")

If tl = vbYes Then

End

End If

End Sub

Private Sub Command2_Click()

txtnguon = Replace(txtnguon, txttim, txtthe)

End Sub