suppress dialog box when downloading files using flash actionscript3 filereference class

I'm trying to set up flash's FileReference class to download files from a publicly accessible web directory to a specific location on my hard drive, without having to use the browse dialogue that is automatically triggered using the download() method. Anyone know how to predef开发者_如何学编程ine a location for the downloaded file so I don't have to trigger the dialogue?

http://livedocs.adobe.com/flash/9.0/ActionScriptLangRefV3/flash/net/FileReference.html#download()

I think they don't allow you to do that because it can be a security risk. You would be able to silently overwrite a user's files or install trojans and such stuff. I don't think there's a way around it.