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Uploading files using AJAX
There is no way to upload files using AJAX. How Gmail does it then? Well, the answer is using <iframe>. Here is a post that describe this technique in detail. Infact we are using this technique from months, obviously inspired by Gmail. 
update: Technically speaking, it’s not Ajax. Just an iframe hack. You are absolutly right Pratik.
November 21, 2006 - 5:40 am
Technically speaking, it’s not Ajax. Just an iframe hack.
So there is no way to upload files using Ajax.
November 21, 2006 - 6:04 am
Some of my AJAX based work -
http://padmanijain.googlepages.com/myexperiments.html
I have used iframes here.
November 21, 2006 - 11:09 am
Hi Pratik,
Obviously this is not AJAX. Infact I have mentioned in my very first line that there is no way to upload files using AJAX.
November 23, 2006 - 7:35 am
“How Gmail does it then?”
Does what ?
November 23, 2006 - 7:35 am
I love how box.net people do it though. Pretty slick UI.
December 20, 2007 - 2:27 am
Oh, and did not know about it. Thanks for the information …