Uncaught TypeError: Cannot read property 'index' of undefined

Mail.elm

import Html.Attributes exposing (style)
import Html.Events exposing (onClick, onMouseDown)
import Html exposing (node, div, text)
import Html.App
import Html.Lazy


type alias Model =
  { color : String
  , clicks : Int
  }


type Msg
  = Click


init : Model
init =
  { clicks = 0
  , color = "black"
  }


update : Msg -> Model -> ( Model, Cmd Msg )
update msg model =
  case msg of
    Click ->
      ( { model | clicks = model.clicks + 1, color = "red" }, Cmd.none )


view : Model -> Html.Html Msg
view model =
  node
    "div"
    [ onClick Click
    , onMouseDown Click
    , style [("font-size", "30px")]
    ]
    [ text (toString model.clicks)
    , Html.Lazy.lazy2 div [] [text "asd"]
    ]


main =
  Html.App.program
    { init = ( init, Cmd.none )
    , view = Html.Lazy.lazy view
    , update = update
    , subscriptions = \model -> Sub.none
    }