Sub Merge_Multi()
  Dim ET As ETGW_Core
  Dim pMxDoc As IMxDocument
  Dim pMap As IMap
  Dim pFL1 As IFeatureLayer
  Dim pFC1 As IFeatureClass
  Dim pFL2 As IFeatureLayer
  Dim pFC2 As IFeatureClass
  Dim pBaseFL As IFeatureLayer
  Dim pBaseFC As IFeatureClass
  Dim pOutFeatureClass As IFeatureClass
  Dim pFeatureLayer As IFeatureLayer
  Dim pFCArray() As IFeatureClass
  Dim sMessage As String
  Dim bDone As Boolean
  Set pMxDoc = ThisDocument
  Set pMap = pMxDoc.FocusMap
  'Merges the first and second layer in the map to the third one
  Set pFL1 = pMap.Layer(0)
  Set pFC1 = pFL1.FeatureClass
  Set pFL2 = pMap.Layer(1)
  Set pFC2 = pFL2.FeatureClass
  Set pBaseFL = pMap.Layer(2)
  Set pBaseFC = pBaseFL.FeatureClass
  ReDim pFCArray(2)
  Set pFCArray(0) = pFC1
  Set pFCArray(1) = pFC2
  '=======================================================================
  Set ET = New ETGW_Core
  Dim sOutFName As String
  sOutFName = "c:\00\test_pgdb.mdb\merged"
  Set pOutFeatureClass = ET.MergeMulti(pBaseFC, pFCArray, sOutFName, sMessage)
  '========================================================================
  If Not pOutFeatureClass Is Nothing Then
    Set pFeatureLayer = New FeatureLayer
    Set pFeatureLayer.FeatureClass = pOutFeatureClass
    pFeatureLayer.Name = pOutFeatureClass.AliasName
    pMap.AddLayer pFeatureLayer
  Else
    MsgBox sMessage
  End If
End Sub