title: External JavaScript file is not getting added when running on Flask
body: <p>I have an HTML file named <code>showMap.html</code>:</p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;!DOCTYPE html&gt;
  &lt;html&gt;
  
  &lt;head&gt;
    &lt;meta name="viewport" content="initial-scale=1.0, user-scalable=no" /&gt;
    &lt;meta http-equiv="content-type" content="text/html; charset=UTF-8" /&gt;
    &lt;title&gt;Map&lt;/title&gt;
    &lt;script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"&gt;
    &lt;/script&gt;
    &lt;script type="text/javascript" src="js/map.js"&gt;&lt;/script&gt;
  &lt;/head&gt;
  
  &lt;body onload="showPosition()"&gt;
    &lt;div id="map_canvas" style="width:500px;height:500px;"&gt;&lt;/div&gt;
  &lt;/body&gt;
  
  &lt;/html&gt;
  </code></pre>
  
  <p>And another JavaScript file <code>map.js</code> is placed in the <code>js</code> folder of the same directory.</p>
  
  <p>This code works fine when the HTML file is loaded, but this does not work when I run it in the server.</p>
  
  <p>I use Python's Flask framework for back-end programming and the funny thing is that the same thing will work well if I expand the JavaScript code inside the HTML file. The only problem is with the external file.</p>