title: how to update the attribute value of json in javascript
body: <p>I have a json file that looks like this: </p>
  
  <pre><code>{
   "@id": "2",
   "@samsid": "d7058536c89b46c0b58117eff64372f7",
   "@productname": "Another paid for",
   "@downloaddate": "2013-05-28 11:37:12Z",
   "@downloadlocation":
      "2AFoGZVJpFHzspQD9UoE2C4VFYc8idiO4ebaRx4uEvtG+79DjkOUjJQjp9lJdSk54KIbFqzr",
   "@upgradeavailable": "2wECEpVJpFHS",
   "@downlaodstatus": "3QGf15VJpFFrUzr6oxwoew=="
  }
  </code></pre>
  
  <p>I want to update the value of the attribute <code>@id</code> eg (<code>@id:2</code> To <code>@id:4</code>).</p>
  
  <p>How would I do this?</p>