title: javascript error [jsonFlickrApi is not defined]
body: <p>I call a FLickrAPI that returns a <code>xmlhttp.responseText</code> that looks like this:</p>
  
  <pre><code>jsonFlickrApi({"photos":{"page":1, "pages":200, "perpage":100, "total":"19934",
   "photo":[{"id":"7315581986", "owner":"62691288@N00", "secret":"504915125a", 
  "server":"7090", "farm":8, "title":"China, Tiananmen Square", "ispublic":1,
   "isfriend":0, "isfamily":0}, {"id":"7308693706",
  ...
  </code></pre>
  
  <p>i try to parse it like this:</p>
  
  <pre><code>var jsonResponse = xmlhttp.responseText ;
  jsonResponse = eval("("+jsonResponse + ")");
  var output += jsonResponse.photos.photo[1].id ;
  alert(output);
  </code></pre>
  
  <p>Firebug tells me: <code>jsonFlickrApi is not defined</code></p>
  
  <ul>
  <li><p>why do i get this error message?</p></li>
  <li><p>why do i have to use 'eval' in the first place?</p></li>
  </ul>