title: Changing javascript context in chrome extension
body: <p>I have an element inside an iframe. If i search on the chrome console for example - document.querySelector(&lt; ELEMENT >) - the element doesn't show up (returns null)</p>
  
  <p>However, if i change the javascript context on the console options, and query again, the element is there.</p>
  
  <p>I want to call that element from a chrome extension.. How can i reference the "document" inside that specific iframe?</p>
  
  <p>The frame element example:</p>
  
  <pre><code>&lt;frame name="SessionA" id="SessionA" scrolling="no" piweb_src="action=../applications/as400/emulator/help.html?IdentTab=SessionA"&gt;
  </code></pre>
  
  <p>The element i want to access example:</p>
  
  <pre><code>&lt;th id="11" onblur="GeneFocusOff(this)" colspan="55" style="color:#FF00FF; "&gt;  RANDOM TEXT &lt;/th&gt;
  </code></pre>