title: HTTP GET Federal Reserve API won't work
body: <p>Apologies in advance, this is a real 'training wheels question'. I am following the instructions on the FRED API (Federal Reserve Bank of St.Louis) website for the HTTP Get request and I keep getting cross-origin errors, but can't find any documentation on how to fix the code.</p>
  
  <pre><code>xmlHttp = new XMLHttpRequest();
  xmlHttp.open( "GET", "http://api.stlouisfed.org/fred/releases/dates?api_key=1cee0e87e5e3362716028352d3d1c160", false );
  xmlHttp.send( null );
  return xmlHttp.responseText;
  </code></pre>
  
  <p>Everything syntaxically is correct, I thought using the site-defined API key would be the only 'authentication' and would let me through? </p>
  
  <p>This is the example link: <a href="http://api.stlouisfed.org/docs/fred/category_series.html" rel="nofollow">St.Louis Fed Web Services</a>
  I have been googling/messing with code for the last 5 hours, can anyone weigh in?  thanks</p>