title: How to change URL form with GET method?
body: <p>Form:</p>
  
  <pre><code>&lt;form action="/test" method="GET"&gt;
      &lt;input name="cat3" value="1" type="checkbox"&gt;
      &lt;input name="cat3" value="5" type="checkbox"&gt;
      &lt;input name="cat3" value="8" type="checkbox"&gt;
      &lt;input name="cat3" value="18" type="checkbox"&gt;
      &lt;input type="submit" value="SUBMIT"&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>How to change URL form with GET method?</p>
  
  <p>Before: test?cat3=1&amp;cat3=5&amp;cat3=8&amp;cat3=18</p>
  
  <p>After: test?cat3=1,5,8,18</p>
  
  <p>I want to use jQuery.</p>
  
  <p>Many thanks!</p>