title: Change querystring without reloading/refreshing
body: <p>I want to change my url on click without refreshing page. For example my URL is <code>http://test.com?search=test</code></p>
  
  <p>When I click any filter value on the search page like "category" then my URL should be:</p>
  
  <pre><code>http://test.com?search=test$category=cat1
  </code></pre>
  
  <p>When I click on another category it should be:</p>
  
  <pre><code>http://test.com?search=test&amp;category=cat1,cat2
  </code></pre>
  
  <p>When I click a brand then the URL should be:</p>
  
  <pre><code>http://test.com?search=test$category=cat1,cat2&amp;brand=br1
  </code></pre>
  
  <p>When I deselect a category then the URL should be:</p>
  
  <pre><code>http://test.com?search=test$category=cat2&amp;brand=br1
  </code></pre>
  
  <p>Please help me.</p>