The issue occurs in IE only. When you run the example, you get an error that says, “‘getElementsByTagName(…).childNodes.0′ is null or not an object.” The problem is not with the JavaScript code itself, but rather a setting in Internet Explorer. Under the Advanced tab in Tools -> Internet Options, enable the checkbox next to “Use HTTP 1.1 through proxy connections.”
This should fix the error. If not, try working on a server (localhost or an online webserver), because operating systems’ file systems differ from that of the Web’s, which is what Ajax uses.

In the Developing Web Applications with Ajax, Pt. 4 article, I mede the example but it fails using FireFox, in the form I wrote:
form action=”http://SomeServer/x/ajax_output.asp” but in Firefox didn’t work. Any Idea. Regards!
July 24th, 2006 at 2:12 pm
Hi Luis,
This may be an issue in regard to security. If you specified a server that is different from the one that the script is being run on, Firefox will ignore the request because it could be a security threat.
July 24th, 2006 at 2:28 pm