title: how to call a javascript function in the top frame?
body: <p>This seems really simple, but how do I call a javascript function that's defined in the top-level html, from a child frame?</p>
  
  <pre><code>top html doc
   - 1st level frame
      - 2nd level frame
  </code></pre>
  
  <p>my top html doc has a function called testFn(). In the 2nd level frame I have a button with <code>onclick="top.testFn();"</code> but this doesn't call the testFn(). In Firebug if I use a watch to execute <code>top.testFn();</code> it says TypeError: testFn() is not a function. </p>
  
  <p>Should this all just work - in which case it's a problem with my documents, or is there some other way to call functions in the top-level window?</p>