title: How to add javascript files to liferay-portlet.xml in liferay project
body: <p>I'm developing an application with liferay 6.0.6 and want to add javascript files to my portlet. If I have two or three javascript files, how could I add them?</p>
  <p>So here is my liferay-portlet.xml :</p>
  <pre><code>&lt;portlet&gt;
    &lt;portlet-name&gt;portletName&lt;/portlet-name&gt;
    &lt;icon&gt;/icon.png&lt;/icon&gt;
    &lt;instanceable&gt;true&lt;/instanceable&gt;
    &lt;header-portlet-css&gt;/css/main.css&lt;/header-portlet-css&gt;
    &lt;footer-portlet-javascript&gt;/js/main.js&lt;/footer-portlet-javascript&gt;
    &lt;css-class-wrapper&gt;portletName-portlet&lt;/css-class-wrapper&gt;
  &lt;/portlet&gt;
  </code></pre>