How I can use UpdatePanel and FileUpload

> Your main option is to look for antoher upload tool.  I know Telerik has some and the Ajax Control Toolkit (free) just came out with an Async upload tool

Funny that this does exactly what the commenter thinks is ugly and maybe insecure: it uses an iframe.

Anyway: your only solution is to use an iframe. You can have it in a complicated way (so that you do not understand that an iframe is being used), or you can do it straightforward.

The reason for this is browser-security.
Updatepanels and other AJAX-like methods send information to the server using javascript, and get information back. Based on the returned information, changes to the DOM in the browser are made.

With fileupload, there is a security issue. For any javascript to upload a file, it would need to have access to the filesystem of the client. For obvious reasons, javascript from the browser is NOT allowed to read files from the filesystem (and upload them). Javascript doing a fileupload behind the scenes is not going to work.

An iframe holds a separate HTML-file, and therefor can be used for fileupload.

The markup in your code isn't ugly, the ACT is easy to deal with (though the rendered markup is still a little ugly).  And their software is tested by many, so security is less of a concern (checking by the masses, may not be correct, but it works for me).

The point is that writing your own is probably not the best approach, as an upload tool does not allow javascript activation due to security issues.

@sybe - no need to add juvinile comments that add nothing to the discussion, we are trying to help answer questions here aren't we?

> we are trying to help answer questions here aren't we?

Yes. And the answer is to use an iframe.

It can be done in a complicated way, by writing a javascript that quickly replaces an input box with an iframe when it is focussed (and changes it back on blur), or it can be done with a static iframe. There is really no difference, except that the javascript solution is needlessly complicated.

I find it remarkable that on one hand you reject an iframe solution, and on the other hand recommend a solution that uses an iframe, but does that in such a complicated way that you do not understand how it works.

I don't really understand the hostility here - I also don't appreciate you assuming you know my skillset.  Either way, not very professional and I am finished with this thread.  OP, I hope you found your solution.