title: How to add or remove a js file in head
body: <p>Suppose I have 3 language: <code>en</code>, <code>tc</code>, <code>sc</code>, I want to achieve the below condition</p>
  
  <p>1) When the current is <code>en</code>, add <code>en.js</code> to head and remove js file <code>tc.js</code> and <code>sc.js</code> in <code>head</code></p>
  
  <p>2) When the current is <code>tc</code>, add <code>tc.js</code> to head and remove js file <code>sc.js</code> and <code>en.js</code> in <code>head</code></p>
  
  <p>3) When the current is <code>sc</code>, add <code>sc.js</code> to head and remove js file <code>tc.js</code> and <code>en.js</code> in <code>head</code></p>
  
  <p>Can someone advise how to do that in jQuery?</p>
  
  <p>Thanks</p>