vb怎么写个一小时倒计时，过了时间到了执行msgbox"一小时到了"

vb怎么写个一小时倒计时，过了时间到了执行msgbox"一小时到了"

我填上1小时或60秒或10分钟钟这样的时间！时间一到就msgbox“时间到了”

以前写的一个，你看看

Dim T As Long

Private Sub Command1_Click()
Timer1.Enabled = True
Label5.Caption = Val(Text1.Text \ 60)
Label7.Caption = Val(Text1.Text Mod 60)
End Sub

Private Sub Form_Load()
    Label1.Caption = "00:00"
    Label5.Caption = "00"
    Label7.Caption = "00"
    Timer1.Interval = 1000
    Timer1.Enabled = False
End Sub

Private Sub Text1_Change()
T = Val(Text1.Text)
End Sub

Private Sub Timer1_Timer()
    T = T - 1
    Label1.Caption = Str(Int(T / 60)) + ":" + Str(T - Int(T / 60) * 60)
    If T = 0 Then
    MsgBox "时间已到!"
    Timer1.Enabled = False
    End
    End If
End Sub