Sub CreateRoutesTwoFields()
  Dim ET As ETGW_Core
  Dim pMxDoc As IMxDocument
  Dim pMap As IMap
  Dim pFeatureLayer As IFeatureLayer
  Dim pInFeatureClass As IFeatureClass
  Dim pOutFeatureClass As IFeatureClass
  Dim sOutFileName As String
  Set ET = New ETGW_Core
  Set pMxDoc = ThisDocument
  Set pMap = pMxDoc.FocusMap
  Set pFeatureLayer = ET.GetLayer("streets")
  Set pInFeatureClass = pFeatureLayer.FeatureClass
  sOutFileName = "c:\00\routes3.shp"
  '=======================================================================
  Dim pGDS As IGeoDataset
  Dim sIdFieldName As String
  Dim pOutSRef As ISpatialReference
  Dim sMessage As String
  Dim sFromMField As String
  Dim sToMField As String
  sIdFieldName = "StreetCode" 'the field to be used as route identifier
  sFromMField = "FromM"
  sToMField = "ToM"
  Set pGDS = pInFeatureClass
  Set pOutSRef = pGDS.SpatialReference 'the output will have the same spatial reference as the input
  Set pOutFeatureClass = ET.CreateRoutesTwoFields(pInFeatureClass, sOutFileName, _
                   sIdFieldName, sFromMField, sToMField, pOutSRef, sMessage)
  '========================================================================
  Set pFeatureLayer = New FeatureLayer
  Set pFeatureLayer.FeatureClass = pOutFeatureClass
  pFeatureLayer.Name = pOutFeatureClass.AliasName
  pMap.AddLayer pFeatureLayer
End Sub