title: NodeJS, Async forEachSeries execution order
body: <p>Just trying to get my head around using Async module for NodeJS.</p>
  
  <p>I have the following code.</p>
  
  <pre><code>var a1 = [1,2,3,4,5,6,7,8];
  async.forEachSeries(a1, function(n1, callback) {
      console.log(n1);
      var a2 = [10,11,12,13,14];
      async.forEachSeries(a2, function(n2, callback) {
          console.log(n1 + " " + n2);
          callback();
      });
      callback();
  });
  </code></pre>
  
  <p>I want to make the process of the above code in such a way that the print out becomes</p>
  
  <pre><code>1
  1 10
  1 11
  1 12
  1 13
  1 14
  2
  2 10
  2 11
  2 12
  2 13
  2 14
  3
  3 10
  3 11
  3 12
  3 13
  3 14
  .....
  </code></pre>
  
  <p>But instead I'm getting something like..</p>
  
  <pre><code>1
  1 10
  2
  2 10
  1 11
  3
  3 10
  2 11
  1 12
  ....
  </code></pre>
  
  <p>How do I fix this?</p>