I have a simple Firebase function that updates some data. However, the interpreter says that the first argument contains undefined in property 'users.tester1'. Can somebody help me please?

var objify = function() {

  var rv = {};

    for (var i = 0; i < arguments.length; ++i)

      rv[arguments[i]] = rv[arguments[i+1]];

    return rv;

}



    addUser(tester1, []);



var addUser = function(name, edges){

  if(!checkIfUsernameExists(name) && !checkIfNodeNameExists(name) && !checkIfEdgeNameExists(name)){

    var time = Firebase.ServerValue.TIMESTAMP;



    //HERE: I think the error is on this line 

    refs.users.update(objify(name, filler));



    refs.users.child(name).set({

      id : time,

      edges : filler

    });

    refs.users.child(name).child(edges).update({

      to : filler,

      from : filler

    });



    addNode(new Node(name, time, name));



    for(var e in edges){

      refs.users.child(name).child(edges/to).update(objify(edges[e].name, true));

      addEdge(new Edge(edges[e].name, time, edges[e].to, edges[e].arrows));

      //TODO add a from edge so that you know who wants to eat you

    }

    refs.users.child(name).child(edges/to).set({filler : null});

  } else {

    alert(user/node/edge name taken.);

  }

};