Firefox扩展-每个页面调用多个XMLHttpRequest

I am trying to create a Firefox extension that can run multiple XMLHttpRequests per page. The code is below (my main function calls the makeRequest on different URLs). My problem is that it always returns (at the "alert('Found ...')" for debugging purposes) the same URL instead of displaying the different responses. I think the issue is that I should somehow pass the http_request instance to the alertContents() function instead of just using http_request directly, but not sure how or if this is correct. Thank you.I am trying to create a Firefox extension that