async-series.js

var steps = [
  function step1(){
    console.log('step1');
    this();
  },

  function step2(){
    console.log('step2');
    this();
  }
];

function doAsync(steps, done){
  var index = 0;

  function doNext(){
    if(index < steps.length){
      steps[index++].call(doNext);
    } else {
      done();
    }
  }

  doNext();
}

doAsync(steps, function(){
  console.log('im done');
});