ajaxComplete, XMLHttpRequest is undefined

I have a global `ajaxComplete` handler: ``` $('body').ajaxComplete(function (event, request, settings) { if (request.getResponseHeader('REQUIRES_AUTH') === '1') { alert("unauthorized"); }; }); ``` The problem in that the `request` always in undefined, is filled only `event`. Can you explain me why? Example of ajax request: ``` $.ajax({ cache: false, data: "GET", url: url, success: function (content) { $('#modal').html(content); $('#modal').modal(); } }); ``` UPDATE: From the API docs (Thanks to Austin Mullins): As of jQuery 1.8, however, the .ajaxComplete() method should only be attached to document. I have change my code to this: ``` $(document).ajaxComplete(function (event, request, settings) { if (request.getResponseHeader('REQUIRES_AUTH') === '1') { alert("unauthorized"); }; }); ``` But now I get the error: ``` TypeError: document.createDocumentFragment is not a function safeFrag = document.createDocumentFragment(); (jquery-1.9.0.js (line 5800)) ``` Browser is Firefox 19.0.2 SOLUTION: The problem was in the Jquery version 1.9.0. I have updated to 1.9.1 and the error is gone. Thanks to Boaz.