SWFUpload: how do I implement an upload handler in ASP.NET?

i'm a novice-to-intermediate .NET developer and I don't quite understand how an upload handler for SWFUpload is supposed to work. Am I supposed to read it from the http stream开发者_开发知识库?

I haven't been able to find any examples or explanation of this in the documentation nor from extensive googling.

Thanks in advance

This is a sample implementation: http://svn.swfupload.org/trunk/asp_net/upload.aspx.cs

More info can be found on SWFUpload website