关于VB的进程管理程序

Private Sub List1_Click() '线程列表
Dim i As Integer
List2.Clear
For i = 0 To Thread32_Enum(Thread(), ProcessId(List1.ListIndex).th32ProcessID)
If Thread(i).th32OwnerProcessID = ProcessId(List1.ListIndex).th32ProcessID Then
List2.AddItem Thread(i).th32ThreadID
End If
Next i
End Sub

‘怎么在这里老提示我，下标越界？