XMLHttpRequest blocked on one page but not another?
<p>I have two pages, both on the same domain. Both are attempting to get an events feed from Google Calendar. One is successful, one is not. The only difference is that one use jQuery's document.ready, and the other uses window.onload. </p>

<p>Page that works: <a href="http://wwwtest.english.wisc.edu/calendar.htm" rel="nofollow">http://wwwtest.english.wisc.edu/calendar.htm</a></p>

<p>Page that doesn't work: <a href="http://wwwtest.english.wisc.edu/844.htm" rel="nofollow">http://wwwtest.english.wisc.edu/844.htm</a> </p>

<p>The second page is being generated by a CMS, so I don't have as much control over the script's loading order, thus I'm using window.onload to ensure the other scripts are loaded first.</p>

<p>*<strong><em>Additional clarifications below</em>*</strong></p>

<p>Yes, I've done debugging, here is the exact error: </p>

<blockquote>
  <p>XMLHttpRequest cannot load
  <a href="https://www.google.com/calendar/feeds/rhrab82ir5qgut1ddv7qj087c8%40group.ca" rel="nofollow">https://www.google.com/calendar/feeds/rhrab82ir5qgut1ddv7qj087c8%40group.ca</a>…ar.google.com/public/basic?start=1356847200&amp;end=1360476000&amp;_=1358694509517.
  Origin <a href="http://wwwtest.english.wisc.edu" rel="nofollow">http://wwwtest.english.wisc.edu</a> is not allowed by
  Access-Control-Allow-Origin.</p>
</blockquote>

<p>But the confusing part for me is this: </p>

<p>I copied the code from the page that works and only changed two things:</p>

<p>1) I changed from using jQuery's document.ready to using window.onload</p>

<p>2) I changed the jQuery selector</p>
