不能播放AVI文件

代码如下:
Private Sub Command1_Click(Index As Integer)
  Dim m As Integer
  If Index = 0 Then
    CommonDialog1.Filter = "avi文件(*.avi)|*.avi"
    CommonDialog1.ShowOpen
    Animation1.Open CommonDialog1.FileName
    Animation1.Play
    End If
    If Index = 1 Then
      Animation1.AutoPlay = False
      Animation1.Stop
      End If
      If Index = 2 Then
         CommonDialog1.Filter = "avi文件(*.avi)|*.avi"
    CommonDialog1.ShowOpen
    Animation1.Open CommonDialog1.FileName
     m = InputBox("请输入播放次数", , "2")
     Animation1.Play m
     End If
     If Index = 3 Then
     Animation1.Close
     End
     End If
End Sub


  运行时,显示" Animation1.Open CommonDialog1.FileName"这句错误."实时错误'35752',不能打开AVI文件.
请问是怎么回事?谢谢