VB计时器代码求解

Private Sub Command3_Click()

End Sub

Private Sub Label1_Click()
    cmdStart.Enabled = True
    cmdStop.Enabled = False
    cmdSZero.Enabled = False
End Sub

Private Sub cmdExit_Click()
    End
End Sub

Private Sub cmdStart_Click()
    tmrCount.Enabled = True
    cmdStop.Enabled = True
    cmdStart.Enabled = False
    cmdZero.Enabled = False
End Sub

Private Sub cmdStop_Click()
    tmrCount.Enabled = False
    cmdZero.Enabled = True
    cmdStop.Enabled = False
End Sub

Private Sub cmdZero_Click()
    lblCount.Caption = "0"
    cmdStart.Enabled = True
    cmdStop.Enabled = False
    cmdZero.Enabled = False
End Sub

Private Sub tmrCount_Timer()
     lblCount.Caption = Val(lblCount.Caption) + 1
End Sub
为什么我编出来的代码安运行他自己就开始计时了。我开始还没点呢。不知道是哪里少了语句