Current state of the Ajax library

A little large to post here, but you can check out the source and an example, where the usage boils down to:

this.request = request_manager.createAjaxRequest();
// For this example, this does nothing, but demonstrates how to set GET parameters
this.request.get = {
  one : 1,
  two : 2
 };
this.request.addEventListener('load', new Array(this, this.ran));
this.request.open('GET', 'xml.php');
return this.request.send();

In order to run the code, a simple new SimpleDemo().run(); will do the trick from Firebug (side note: sample only tested from Firefox - let me know how it fares in other browsers).

Basically, I need to ensure that usage like this makes things easier to read and port to other libraries. I honestly don't care if anyone actually uses this library, I just want the usability and abstraction to get through. The Ajax portion weighs in at just under seven kilobytes, including white-space, comments, and full names so you can actually read it, and I have every intention on keeping it that way. I've included a reference to Firebug Lite, just in case you don't have the full version installed.

Edit: okay, so the source code viewing works in Opera, but not Safari, and calling run(); from Firebug Lite pretty much does squat in either of them. Editing will commence, but I will still greatly appreciate any feedback and criticism.