     # set range if known
     opts.valueRange = [ 0, 100 ]
 
+  ####
+  # custom zoom/pan handling
   opts.interactionModel = _.clone(Dygraph.Interaction.defaultModel)
 
   # override mousedown to allow toggling pan mode

  footer_text = sprintf("Last Value: %0.2f%s", last_val, unit)
  footer.text(footer_text)

  opts = {
    labels: [ "Date/Time", "v" ]
    strokeWidth: 2


  }
  g.updateOptions(opts)

  return g


