title: Javascript Google Geocode Returning Undefined (Can't figure callback function)
body: <p>I'm trying to store the values of the latitude and the longitude from the response that I get from the Google Geocoding API. Right now I am using a fixed location in California. My HTTP request keeps returning undefined.</p>
  
  <p>I've been looking around a lot and I see that people have this same problem, but I can't wrap my head around making a callback function which seems to be the solution, could anybody explain to me how to do this? I know that my CORS request is working because I am using it to talk GET from a Heroku server that I set up.</p>
  
  <pre><code>var geocode = new XMLHttpRequest();
  geocode = createCORSRequest('GET', 'https://maps.googleapis.com/maps/api/geocode/json?address=1600+Amphitheatre+Parkway,+Mountain+View,+CA&amp;key=');
  
  geocode.onload = function() {
      var geoData = JSON.parse(geocode.responseText); // parse the JSON from geocode response
      var results = geoData["results"]; // create variable for results
  
      var userLong = results["geometry"]["location"]["lng"]; // parse the latitude
      var userLat = results["geometry"]["location"]["lat"]; // parse the longitude
      console.log(userLong);
      console.log(userLat);
  }
  </code></pre>
  
  <p>createCORSRequest()</p>
  
  <pre><code>// Create the XHR object.
  function createCORSRequest(method, url) {
  if ("withCredentials" in xhr) {
    // XHR for Chrome/Firefox/Opera/Safari.
    xhr.open(method, url, false);
  } else if (typeof XDomainRequest != "undefined") {
    // XDomainRequest for IE.
    xhr = new XDomainRequest();
    xhr.open(method, url);
  } else {
    // CORS not supported.
    xhr = null;
  }
  return xhr;
  }
  </code></pre>