Thanks very much for your reply.
Well, I am using version 3.0 of Ajax Uploader. I have downloaded it from downloads link of http://ajaxuploader.com
I am also using the same code as you provided me in your reply but getting Upload button disabled as soon as I click on it. No file browser windows opens and button becomes disabled. I am very dissapointed with this.
With Regards
Kazam Raza.