title: Why IntelliJ Idea doesn't recognize the dollar operator of JQuery?
body: <p>IntelliJ shows a warning "<em>Unresolved function or method $()</em>" when mouse over the <code>$</code> sign despite the file is in the same directory as js file. So I can't take advantage of intellisense when typing <code>$</code> functions. </p>
  
  <p>Just one line of code and the IDE didn't recognize it. But it works. How can I fix this problem?</p>
  
  <pre><code>$(".container").get(0).appendChild(proDiv);
  </code></pre>