如何用VB程序做计时器？

3个标签，2个按钮，1个计时器控件
Private Sub Command1_Click() '开始/暂停
If Timer1.Enabled = True Then
Timer1.Enabled = False
Else
Timer1.Enabled = True
End If
End Sub

Private Sub Command2_Click() '停止清0
Label1 = "0"
Label2 = "0"
Label3 = "0"
Timer1.Enabled = False
End Sub

Private Sub Form_Load() '初始设置
Label3 = "0"
Label2 = "0"
Label1 = "0"
Timer1.Interval = 1000
Timer1.Enabled = False
End Sub

Private Sub Timer1_Timer()
Label3 = Label3 + 1
If Label3 = 60 Then
Label3 = "0"
Label2 = Label2 + 1
If Label2 = 60 Then
Label2 = "0"
Label1 = Label1 + 1
End If
End If
End Sub