More on the XMLHttpRequest
One of the things I noticed right off is that while it is a pain to use the xmlhttprequest object, it is way faster than using iframes. Most of the people who have been doing it for a while are probably like duh! But I hadn't been using it much so I didn't notice how much overhead managing the iframe was. I will upload the code as a zip toward the end of this post, and I won't go into the class itself, but I will just drop a hint as to how to instantiate it.
The second command tells the new instance of the xmlhttprequest to execute. Whenever it comes back, the function will be tripped and everything is good.
Its a good read and it helped me get along with using it.
Here are the files, enjoy!