Excel always error??

[alee001]

Why Excel always error and stop during run follow code? [let Cells(2,2)=10]

Private Sub CommandButton1_Click()
Cells(2, 1) = 0
Call StartData
End Sub

Private Declare Function SetTimer Lib "user32" (ByVal hWnd As Long, ByVal nIDEvent As Long, ByVal uElapse As Long, ByVal lpTimerFunc As Long) As Long
Private Declare Function KillTimer Lib "user32" (ByVal hWnd As Long, ByVal nIDEvent As Long) As Long
Dim hTimer
Dim BarNo As Integer

Sub CloseData()
On Error Resume Next
Call KillTimer(0, hTimer)
End
Exit Sub

End Sub

Sub StartData()
On Error Resume Next
BarNo = 0
hTimer = SetTimer(0, 0, 1000 / 1, AddressOf Main)
End Sub

Private Sub Main()
On Error Resume Next
BarNo = BarNo + 1
Cells(2, 1) = BarNo
If BarNo > Cells(2, 2) Then
    Call CloseData
    End
End If