I finally realised the problem with swfupload...
I have a page used to process the uploaded file in swfupload but previous problem I had, I couldn't reach to the page to do the processing. Now I know why, it is because the authentication problem.
The server thought the user hasn't been authenticated when the swfupload trying to upload
Does any know how to let server knows the user has been authenticated?
Some people say using Authenticate ID... How to I do that.
Plz help
p.s I am using asp.net