Add an axis in a selected part shape.txt

Oh, I'm sorry about this subprogram is still has its defect maybe you'll find it soon.
I want to tell you the forgoing idea of mine like the artical theme but I am failed. If there have many shapes in the body, the axis whould have been created in the last shape.
If you have any kind idea, pelease show it to me. 
Sub AddAxisInPartShape()
    Dim partDocument1 As PartDocument
    Set partDocument1 = CATIA.ActiveDocument
    Dim part1 As Part
    Set part1 = partDocument1.Part
    Dim hybridShapeFactory1 As HybridShapeFactory
    Set hybridShapeFactory1 = part1.HybridShapeFactory
    Dim SelObj, oSel As Selection
    Set oSel = partDocument1.Selection
    If oSel.Count = 0 Then MsgBox "Please select a suitable element": Exit Sub
    Set SelObj = oSel.Item(1).Value
    If InStr(SelObj.Name, "Selection_") <> 0 Then
        Set SelObj = SelObj.Parent
    End If
    MsgBox SelObj.Name
    Dim hybridShapeAxisLine1 As HybridShapeAxisLine
    Set hybridShapeAxisLine1 = hybridShapeFactory1.AddNewAxisLine(SelObj)
    hybridShapeAxisLine1.AxisLineType = 1
    Dim hybridbodies1 As HybridBodies
    Set hybridbodies1 = part1.HybridBodies
    If hybridbodies1.Count = 0 Then hybridbodies1.Add
    hybridbodies1.Item(1).AppendHybridShape hybridShapeAxisLine1
    part1.InWorkObject = hybridShapeAxisLine1
    part1.Update
End Sub