It depends on whether you want #notifyState to use setTimeout or not. If you don't need the setTimeout then you just re-write as follows:

var notifyState = function(state) {

  /* Do something */

}



notifyState('State 1');

notifyState('State 2');

If you want to keep the setTimeout and chain the calls, so that the second notify is executed after the first, you will have to provide a callback:

var notifyState = function(state, callback) {

  setTimeout(function() {

    /* Do something */

    if (callback) {

      callback();

    }

  }, 2000);

}



notifyState('State 1', function() {

  notifyState('State 2');

});

EDIT

Seems that the OP problem is different. My understanding is that your are providing #notifyState function as a callback to a 3rd party Flash that you don't control and you want to ensure that calls to notifyState execute in the same order and one after another, so you don't have 2 parallels calls to notifyState running at the same time. To achieve this you will need to introduce a queue that will keep the states and change the notifyState function in a way to execute only one state at the time. I will assume your need for the setTimeout is important here and keep it that way. See the code below:

var Queue = [],

    running = false;

var notifyState = function(state) {

  if (running) {

    Queue.push(state);

  } else {

    running = true;

    setTimeout(function() {

      /* Do something */

      running = false;

      var nextState = Queue.pop();

      if (nextState) {

        notifyState(nextState);

      }

    }, 2000);

  }

}