title: can't remove parameter using javascript
body: <p>i have a url like this</p>
  
  <pre><code>test.html?dir=asc&amp;end_date=2016-09-23&amp;order=created_at&amp;start_date=2016-08-14
  </code></pre>
  
  <p>i want to remove the parameter using the following javascript</p>
  
  <pre><code>function removeParam(uri) {
  
     uri =  uri.replace(/([&amp;\?]start_date=*$|start_date=*&amp;|[?&amp;]start_date=(?=#))/, '');
  
     return uri.replace(/([&amp;\?]end_date=*$|end_date=*&amp;|[?&amp;]end_date=(?=#))/, '');
  }
  </code></pre>
  
  <p>but it didn't work, anyone know what's wrong with that?</p>