A multipart upload consists of combining individual parts to create a single HTTP request to the server. TO run this scenario, copy the MultipartUpload.aspx page from the MultipartUploadServer folder in Chapter 14's companion content to the localhost's BackgroundTransferSample folder, or run that website in Visual Studio for Web. That page will write the contents of the upload request to a mutlipart-request.txt file in the server folder. Here, on the client side, pressing the Start Multipart Upload button will begin a transfer of tinyimage.jpg where the request contents will closely mirror those showsn in the Flickr upload POST example on http://www.flickr.com/services/api/upload.example.html.