title: How to mask/hide URL params on and off with javascript without refresh?
body: <p>As the question states, how do you hide/unhide/mask URL query parameters in javascript? This site appears to be able to do something like it:</p>
  
  <pre><code>http://bernii.github.io/gauge.js/#!
  </code></pre>
  
  <p>(Check the  "Share it! If checked, the option values will be stored in the URL so that you can easily share your settings.")</p>
  
  <p>Say I have the following URL...</p>
  
  <pre><code>http://localhost/?var1=value1&amp;var2=value2&amp;var3=value3
  </code></pre>
  
  <p>How do I hide just the var2 and var3 portion such that the URL is:</p>
  
  <pre><code>http://localhost/?var1=value1
  </code></pre>
  
  <p>(WIth a click of a link on the page to toggle the GET variable in and out of the page without refreshing it.)</p>