title: convert string to json array
body: <p>I get this response from an Ajax request.
  Javascript seems to intepret it as a string.
  (When I say alert this.responseText, the whole string is shown)</p>
  
  <p>How can i convert it to a javascript object (JSON)?</p>
  
  <pre><code>{"response": {
     "success": "The activity has been removed",
     "message": "0"
  
    }
  }
  </code></pre>
  
  <p>I am not using jquery.</p>