TerrainLightMapper isisn't a member of Unity Editor

i telecharged the demoIsland de unity 3d. when i try to open it with Unity 3.3 i saw this error: (Assets/Editor/UpdateTreeColors.js(13,29): BCE0019: 'TerrainLightmapper' is not a member of 'UnityEditor'.) so i tried to open the script " UpdateTreeColors.js" and i commented "//" this 2 lines:

1. line of the function static function RebuildWithLightmap ()

//UnityEditor.TerrainLightmapper.UpdateTreeLightmapColor(tex, Terrain.activeTerrain.terrainData);

1. line of the function static function RebuildWithColor () //UnityEditor.TerrainLightmapper.UpdateTreeColor(tex, Terrain.activeTerrain.terrainData);

so the scene became as shown in this figure:

http://i54.tinypic.com/idhtoj.png

please help me!!