Terrain set detail layer problem.

Ok, so I have this terrain that cuts itself up and then places stuff on. This code I have places details on the terrain using the Terrain scripts detail prototypes. However it only places the first detail in the list. I cannot get it to place anything other than the first. The last integer at the end of GetDetailLayer is supposed to do it but, nothing shows up if I change it to above 1. Setting it to 1 still only shows the first detail. I'm very confused please help. It should be working, I don't get it.

    void PlaceDetail(Terrain t, Vector3 pos, float radius)
     {
 
         int TerrainDetailMapSize = t.terrainData.detailResolution;        
         float pixelSize = TerrainDetailMapSize / t.terrainData.size.x;        
         Vector3 TexturePoint3D = pos - t.transform.position;
         TexturePoint3D = TexturePoint3D * pixelSize;    
         float[] xymaxmin = new float[4];
         xymaxmin[0] = TexturePoint3D.z + radius;
         xymaxmin[1] = TexturePoint3D.z - radius;
         xymaxmin[2] = TexturePoint3D.x + radius;
         xymaxmin[3] = TexturePoint3D.x - radius;
         int[,] map = t.terrainData.GetDetailLayer(0,0, t.terrainData.detailWidth, t.terrainData.detailHeight, 0);
         for (int y = 0; y < t.terrainData.detailHeight; y++) {
             if(xymaxmin[2] > y && xymaxmin[3] < y)
             {
                 for (int x = 0; x < t.terrainData.detailWidth; x++) {                
                     if(xymaxmin[0] > x && xymaxmin[1] < x)
                         map[x,y] = 1;
                 }
             }
         }
         t.terrainData.SetDetailLayer(0,0,0,map);
         t.Flush();