Terrain Toolkit and Texturing via Code HELP!

I am having trouble getting the TerrainToolkit.TextureTerrain to work... It give the error message that the heightStops array is out of range. Or at least I think its the height stops.

What am I doing wrong?

     public Texture2D[] desertTextures;
     //
 
 
 
 
     void Start () {
 
 
         //Set textures....
 
         float[] sStops = new float[2]; 
         float[] hStops = new float[4];
 
         Texture2D[]tTexs = new Texture2D[1];
 
         sStops[0] = 30f;
         sStops[1] = 70f;
 
         hStops[1] = Random.Range(0.05f,0.18f);
         hStops[2] = Random.Range(0.19f,0.28f);
         hStops[3] = Random.Range(0.5f,0.48f);
         hStops[4] = Random.Range(0.7f,0.80f);
 
         this.GetComponent<TerrainToolkit>().TextureTerrain(sStops, hStops, desertTextures);
 
     }
     
 
 }