finding and updating a mongo object with casbah, clueless edition

Mongo.scala

  def putStat[T](id: String, k: String, v: T, coll: MongoCollection = ms): Unit = {
    Console.err.println("putting mongo stat: _id->%s, %s->%s".format(id,k,v))
    val newVal = Map(k -> v)

    coll.findOneByID(id) match {
      case Some(obj) => coll.update(obj, obj + (k -> v))
      case _         => coll.insert(MongoDBObject("_id"->id, k->v))
    }
  }