求教！

HI , Good morning everyone ,请指点一下：“Set Nftr1 = Map1.Layers.Item("Try").Selection.Item(1)“这句的错误是："No object was found using the index you specified" Why? thanks!
Dim Nftr1 As Feature
Dim Nftr2 As Feature
Dim ff As FeatureFactory
Dim Myftrs As Parts
Dim Myftr As Points
Dim pnts As Points
Dim pnt As Point
Dim Npnt As New Point
Dim Npnts As New Points
Dim MyNftr As Feature
Dim x As Double
Dim Y As Double
Set Nftr1 = Map1.Layers.Item("Try").Selection.Item(1)
Set Nftr2 = Map1.Layers.Item("Try").Selection.Item(2)
Set ff = Map1.FeatureFactory
  If ff.IntersectionTest(Nftr1, Nftr1, 1) Then
    MsgBox "交*", , "提示"
    Set Nftr = ff.CombineFeatures(Nftr1, Nftr1)
    Set Myftrs = Nftr.Parts
    For Each Myftr In Myftrs
      Set pnts = Myftr
      For Each pnt In pnts
        x = pnt.x * 1 / 2
        Y = pnt.Y * 1 / 2
        Npnt.Set x, Y
        Npnts.Add Npnt
      Next
        Set MyNftr = ff.CreateRegion(Npnts)
        Set MyNftr = Map1.Layers(1).AddFeature(MyNftr)
        MyNftr.Style.RegionColor = RGB(255, 0, 0)
        MyNftr.Style.RegionPattern = miPatternDiagCross
        Map1.Layers.Item("Try").AddFeature MyNftr
        MyNftr.Update
      
    Next
  Else
    MsgBox "无交*", , "提示"
  End If
<img src="images/post/smile/dvbbs/em09.gif" />

but ,确实存在呀！