title: how export variable in ES6 in Chrome/Firefox?
body: <p>In latest versions of Firefox and Chrome, I try make export variable.</p>
  
  <p>index.js:</p>
  
  <pre><code>'use strict'
  import { bla } from './helper';
  console.log(bla);
  </code></pre>
  
  <p>helper.js:</p>
  
  <pre><code>export var bla = 20;
  </code></pre>
  
  <p>but Chrome console display follow error message:</p>
  
  <blockquote>
    <p>Uncaught SyntaxError: Unexpected reserved word</p>
  </blockquote>
  
  <p>firefox console display follow error message:
  SyntaxError: modules are not implemented yet</p>
  
  <blockquote>
    <p>import { bla } from './helper'; &lt;--</p>
  </blockquote>
  
  <p>also I try follow variant index.js:</p>
  
  <pre><code>'use strict'
  import { bla } from './helper.js';
  console.log(bla);
  </code></pre>
  
  <p>also I try follow variant index.js:</p>
  
  <pre><code>'use strict'
  import { bla } from 'helper.js';
  console.log(bla);
  </code></pre>
  
  <p>but the error message remains the same.</p>